800×600 pixels

that depends on the size of your page too.. It doesnt matter actually. Myspace resizes the picture. in case its too small, it tiles it.. so the dimensions of the picture are not important

This question actually doesn’t have an easy answer. The reason why is because myspace users have probably the most varied audience of all or any social networking sites and because they are behind the times as far as how you build your pages myspace is not flexible enough to accommodate them all. So a simple solution I found was to steal other backgrounds and build my new one on top of that. Right now 800 x 600 seems to fit best for the vast majority of myspace users but I found that now people are migrating towards making a 1280 x 1024 background that have a different middle portion to cater to people with larger monitors and higher resolutions but it can also be visible to people with standard resolution. I have included a link to a background I’ve done as an example but the simple answer would be 800 x 600px. I hope this helps.