The answer is not as easy as there are not as detailed documentation as for other technologies.

Do you search for BigTable documentation or for opensource-alternatives?

HBase is a near-clone of Google’s BigTable.
Cassandra is more a BigTable/Dynamo hybrid.

A nice introduction i can remember was Ricky Ho’s NOSQL Patterns from Nov. 2009 [1].

Of course there is the common overview, you know yet:
- Ian Varley’s master thesis from 08/2009 [2]
- some Cassandra slides from 2009 [3]
- a slideshare presentation on “Key-Value stores: a practical overview” by Marc Seeger (Stuttgart 2009) [4]

Maybe some coding examples [6] help or
stumble through the Casandra homepage [7].

If you prefer learn by doing, have a look on this cool Casandra tutorial of Evan Weaver from Twitter [5].

[1] Ricky Ho’s NOSQL Patterns Nov. 2009
[2] Varlay Master Thesis Aug. 2009
[3] Some Cassandra slides 2009
[4] Key-Value Stores – a practical overview by Marc Seeger 2009
[5] The Cassandra Tuturial by Evan Weaver July 2009

[6] Cassandra Client Examples
[7] Cassandra Getting Started

Hope this help.

Update

I forget to mention this helpful tutorial on database modeling with Casandra
“WTF is a SuperColumn? An Intro to the Cassandra Data Model” [8] by Digg’s Arin Sarkissian.

[8] WTF is a SuperColumn? An Intro to the Cassandra Data Model Sep. 2009

2) Clarify (the situation, problem, or opportunity)

3) Create (the idea for the proposed solution, budget, flexibility, alternatives)

4) Change (the impacts, human issues, what-ifs, stakeholder landscape)

5) Confirm (the measurements of success, who/how/when)

6) Continue (think about how to ensure lasting success, risk avoidance, success factors)

7) Close (lessons learned, benefits followup, help client become self-sufficient)

The Seven Cs of Consulting: The definitive guide to the consulting process

But what happens if Google will buy them?

It will create a direct competitor to all journalists and existing media channels, like Fox News, CNN or BBC.
Twitter users as “Citizen journalists” will post their stories and have adwords. They will publish their pictures on Twitpic and get paid for it.

Good news or bad news? It depends. Twitter isn’t an open platform, it is again an user silo. Good for Twitter, good for Google, sometimes too much in transparent for it’s users.

Google tried to realize the same deal with Jaiku 2 years ago.
Jaiku was a niche community before Google. After the deal more and more spammer joined Jaiku.
Last year Jaiku failed and Google gave up the project
(it will be opensource, but for me the project failed).

The biggest fact: a Google/Twitter deal will initiate a worldwide inflation of new Twitter users. Those news will spread the Twitter community worldwide,
because Google knows everybody and a lot of people will look on Twitter, if Google will announce the deal.

But what happens to Twitter, if the big news will spread and more and more users and more and more spammers will join Twitter?
Maybe it will be harder to track real information or to filter the right value for me.

So it’s time to jump on an open Twitter alternatives, let’s be more active on Identi.ca …

Ok, for search we have a lot of alternatives, like Yahoo, Digg etc.

It’s all about competition and searching alternatives for a service we use.
If you drive a Ford and you are unhappy with your Ford, you can buy a Golf or a BMW.

So, for microblogging it must be a good idea to have an alternative to Twitter: Identi.ca.
Twitter is closed source completely, but Identi.ca is based on opensource for Microblogging.
The service Identi.ca is an Open Source, CreativeCommons framework for a distributed network of federated microblogging services, based on Laconi.ca.

* What happens, if Twitter is down?
* What happens, if Twitter will grow and have more and more “marketing spam”?
* What happens, if Twitter will filter messages in future and we user cannot review what they do?

Microblogging is about people. So we will see, what the future will bring us.
But is there room to live beside Twitter (Google will close Jaiku as alternative, they not really stop the project, but put it opensource)?

Identi.ca have some good potentials to grow as service like Twitter in the same way as we have different
messaging networks like MSN, ICQ, Yahoo, Google Talk.
Why not push Identi.ca with some good ideas from the opensourced Jaiku…

I’m looking forward to see future applications for Identi.ca, like Twhirl or Tweedeck for Twitter.
It should not be as hard as Identi.ca offer a similar API like Twitter.

Twitters first growth was based on their first-mover status, then they grew up based on fantastic applications from the community based on their public API,
but has Identi.ca a chance to jump on this wagon?

The core technology behind XMPP was invented by Jeremie Miller in 1998, refined in the Jabber open-source community in 1999 and 2000.

Listen to his interesting interview:

Another presentation from Barcamp Bangkok show some interesting Asian of African web projects:

Why, there are so many applications out there without following the W3C recommendations:

• Keep content consistent and structurally simples
• Provide easy means of navigation
• Avoid free text input whenever possible
• Use small individual markup documents
• Avoid embedded objects of scripts

Sounds easy? The same simple rules can be adopt to all web applications around. When visiting eBay, have you ever been asked to “look carefully, because the order of any menu options have been changed” or when returning to Amazon (the early one, today a lot of pages at Amazon are overloaded), did you ever need to navigate through five levels of menus just to see whether your order has shipped?

The Product Guy wrote some words about a quick assessment of user experiences:

The Quick-UX evaluates the degree to which a product successfully addresses the following 3 questions:

* Can I use it? (Usability)
* Should I use it? (Usefulness)
* Do I want to use it? (Desirability)

Keep all applications small and simple!

Google followed with its own announcement, that Google accounts would serve as OpenID accounts.

We know, Yahoo has supported OpenID for a while now, anyone using Gmail, Yahoo Mail or Hotmail now has a valid OpenId.
Additionally MySpace and AOL also support OpenID.

Most current users may not be aware of the fact they have an OpenID identifier.
It would be quite interesting
* what are the biggest OpenID providers derived by the frequency of OpenID usage?
* what is the usage ratio between “big” providers and the many users from small OpenID providers?
* Are public small openID providers interesting for mass user? Should any small company or community run an identity server?

Yahoo release the result of a usability study, they did for OpenID.

Jan Rain hast posted results to 6 general UX approaches for OpenID from the Open User Experience (UX) Summit.

In parallel to the UX discussion the most important topic to OpenID is security and privacy for me.
They are currently discussed in the community, but for me not fully answered:

* what about identity revocation, if anybody else get my key?
* what about phishing prevention?
* what about trusted OpenID provider? who can we trust?
* what about privacy of my user data (customer profile, mixed private and business usage)?
* what if my OpenID provider sell my profile, usage or my network data to anybody else?
* what, if there is a legal case to one of my accounts, how to prevent all account access due to any legal case?
* what, if my OpenID provider no longer exists?

OpenID is a great way to reduce our daily account/password overflow and to get easy access to small sites or to test new services.
But is there a more secure way to share email access, private or business data?