(Flash flattens hard disks)
I recently added a 512 GB SSD to my Mac Pro desktop. The gain in speed is amanzing, especially for startup and opening applications. Dancing dock icons entertain only once … now apps open immediately, and the gain in daily work still amazes me. For Unix (which sits behind the Mac's pretty windows) everything is a file, but that also means that it has to constantly access a lot of files, which is just the thing an #SSD is best for. Subsequently we equipped a number of student desks with SSD-sporting Mac Minis (also upping RAM to 16 GB), and these are really nice. [Of course, it's a given that CPU-bound processing doesn't speed up.]
I haven't yet shelled out the money to up my personal portable since prices are still coming down. In the meantime, one can entertain oneself by reading the nice in-depth description of flash memory, how it works plus pros and cons at ars technica:
I you still are contemplating a Christmas present for yourself: here's one.