Recently I found that it was taking appauling amounts of time to transfer files to/from my debian file server setup with netatalks AFP. I upgraded to the latest version to no avail, but this trick helped out quite a lot — http://www.netafp.com/tn003-slow-afp-read-performance-90/
Incidentally I believe, unscientifically, that it also helped my OnLive game latency quite a lot (on OSX)
I've been using smb instead of afp on linux for years. Works like a charm.
@Stephane From what I understand this helps with the speed of SMB transfers as well.