My first SSD was a OCZ Vertex (120GB). I put that SSD in my desktop (as a OS drive) and it was fast. I later figured it would be even better in my laptop because I'd get durability benefits, increased battery life and the performance benefits.
Unfortunately, while you do notice a bit when you go from a slower drive to a faster drive, you
really notice when you go from a faster drive to a slower drive, and my desktop, back to running on spinning rust, was a slug.
Sigh.
So, I then picked up a Intel X25-M (160GB) for my desktop and all was well again. Here is how I justified it to myself: when you take your total system cost as a whole into consideration, adding a ~$200-$500 SSD is a lot of money, but if it makes your total system cost only 30% more expensive but at the same time makes your computer feel twice as fast, that isn't such a bad trade-off. Think in terms of dollars per gigabyte and you'll never buy a SSD. Instead, thinking of dollars per unit performance, and SSDs look like a much better value.
http://techreport.com/r.x/ssd-value-0610/value-price-overall-plot.gif
Oh, and:
Intel announced today that it is lowering the price of its existing 80GB and 1600GB solid-state (SSD)
... should be 160GB, not 1600GB. Unfortunately.