For me it's "your" (belongs to you) and "you're" (you are).
Related:
"its" (belongs to it) and "it's" (it is)
Or something like that. Too early in the morning.
zen
::edit::
P.S. Spyder, isn't it 'hear, hear'? I'm such a bastard.
[This message has been edited by zenbudo (edited 05 March 2001).]