MultiBit is a desktop client for Windows, Mac and Linux. It is written in Java and uses bitcoinj for talking to the bitcoin network.

The main website with screen shots, download details and help is:

http://multibit.org

MultiBit's main feauture are:

1. Completely open source. MIT licence.
   
2. Easy to use. Easy to run from a USB drive.
   
3. Support for multiple wallets (though automatic rescan is not done yet).
   
4. Small footprint- the current blockchain is less than 16MB from the genesis block.
   
5. You can create QR codes of addresses in the bitcoin URI format. You can drag and drop these to and from the app.
   
   

Important Limitations:

MultiBit is experimental code - do not use it for large amounts of bitcoin. 

The wallets are not encrypted. (This is a planned development).

I hope  you like it.