1 SSD or 2 SSDs?

RAID 0 won't get along with TRIM

If you get two, you can put them into Raid0. 0 means the amount of data that you will be able to recover after a failure. :P Or a raid1 which provides a good security against data loss. OR you can use one as a system drive and one for other stuff.. I don't really see a point in that. (However, if you tend to use Windows 7 (you should use that since its optimised for SSD), it'll eat your 30gb with a single bite. You should take the 60gb or two 30gb with RAID0 :))

Have a look at http://www.anandtech.com/show/3618/intel-x25v-in-raid0-faster-than-x25m-g2-for-250 - they tested this scenario.

I have 2 laptops with SSDs, one of them also has a spinning drive for all my junk. I'd go for 1 big drive in a laptop, please yourself in a desktop if you have space. That decision could depend more on cost and availability than on performance differences which may, or may not be noticeable.

2x SSDs won't be twice as fast as one and it won't be twice the difference from spinning rust. The 1st SSD is the order-of-magnitude difference, the 2nd is hte icing on the cake.