Absolutely. I've taken an old ok-performing HP desktop, popped the SSD in for the system drive, and now it's like a race car.
Same recommendation I give others - grab the cheapest SSD you can find to meet your storage needs. For yours - buy a 60GB for $60 to $80, put the OS on it, and then use your current drive for data.
Another recommendation - you'll do yourself a big favor upping your memory to 4GB. Memory is cheap these days - don't skimp on it. Take the memory to 4GB (maybe cost you $30 if you have to throw away your existing 2GB) along with the SSD and you'll have yourself a speedster.