I'm using an SSD in my desktop, my SSD supports TRIM which means it can optimise the drive to counter various negative aspects of SSD (i.e. marking parts of the drive not to use again).
It as an absolute revelation in performance. The PC is virtually silent (actually, the SSD is silent obviously), boots up very quickly indeed (15 seconds from the BIOS to a fully loaded Windows 7 OS) and shuts down similarly quickly. Appllications launch instantly, so fast you couldn't manually time them anyway.
SSD is too pricey to use as pure storage, so I only have my OS and a few often used applications on the SSD, I have a standard SATA HDD for storage and large app installation like games etc. As soon as they're cheap enough I'll be buying a newer larger SSD so I can install some of my larger apps on it.
SSD is the way forward, particularly laptops (lower power consumption, more robust etc).