best distro for mobility ATI ?

[sybn]

besides ubuntu, what others distro offer good support to my 4650 mobility radeon from startup.

[Kano]

You can install latest fglrx driver on kanotix with 2 simple commands, newer than the version in the u repo, patched to support .39 kernel. If you are a fan of oss drivers i have got a few scripts to compile tha latest git snapshots of those drivers as well.