One major thing that will save space is to move the "My Documents" and other "Libraries" folder to another drive.
This is what we then call a data/media drive. Simply drag and drop them from the "Users" folder on the C drive, and Windows 7 will then point to the new location as default for "Libraries."
So keep the original drive, and use it for data/media/storage/backups.
Take a look at the size of these library folders, and see if moving them would free up alot of space. My Win7 drive only uses 22GB of my 80GB RAID 0 SSD array. But don't go this route, it's complicated to RAID SSDs.
If so, I'd suggest an Intel X25-M 80GB G2 SSD. $219.99 here.