A 120GB drive is going to store a fair amount of stuff, I have 3 games, my OS and some other programs on my 60GB drive. Install your favourite or long loading games onto the SSD, and move them to the HDD when you've moved on and want to throw a new batch of games onto the SSD.
Because of low seek times, an SSD allows games to load far quicker than 2 drives in Raid0 can.
but i knew it was only faster load speeds
thats what i cared about, load speeds
i plus rep'd ya