Samsung Spinpoint F1 partitions

Hello,

I have a simple question concerning my new HD Samsung Spinpoint F1 1TB:
Should i partition it into 2 500 go partitions or leave it as one big partition of 1To?
I was thinking about using the first 500 go for installs (from phtoshop to games, lot of them ) and the second one for storing mp3s, videos, emulation romolections...
I'm not familiar with HDs of that speed and that size, so i was wondering if it was still advisable to create separate partitions?

Hello JSC, yes it is my boot (and only) drive.

I was thinking about doing like this:

A. 500Go partition for all programs (winxp, photoshop, games, video tools,...)
B. 500Go partition for documents, music, emulation roms,...

So the day i need to make a format or a defrag because of all the installs/uninstalls, 20 firefox updates,... i only need to take care of the partition A.
Which would make it much faster in terms of backups and chkdsk,...

Do you think it is useless and that i should leave it as it is, everything on the same partition?