Hi
   this is question to all of you, that have experience with application platforms other than MySpace. (Facebook, Bebo, LinkedIn, Hi5, Orkut, Netlog, etc.) 

Did you implement app. for MySpacefirst and after that, tried to apply it to different platform ? If yes, then what main problems did you encounter ? Was it rather easy or difficult ?
If you compare MySpace's API with another one, which one was better ? What are pros and cons of each of these APIs ?
What are your feelings about OpenSocial ?

thx
Luk