Personally, I prefer non-static stuff.
Statics (that which moves with you) tend to impose their presence overmuch. Besides not every browser can take them, so if you want to appeal to as many users as possible, it's best to use standars over statics.......I think.
If you insist on using statics, I think it's best using one you can pull in and out at will, but static is static whatever, and I tend not to stay too long on a page that has one.