I recently purchased a Queen Size Memory Foam 10" Mattress for myself this Christmas. Not one of the really expensive ones but a cheaper knock off brand from overstock.com. I had previously been sleeping on an old mattress that I bought at least 8 or 9 years ago. Wow. The difference in comfort is amazing and I am sleeping better than ever now that I switched.
What is even more amazing is how they shipped the darn thing. It was shipped rolled up and vacuum sealed so that it was only about 1/3 the size of the full mattress. Fed Ex basically just dropped it off on my front porch so it was just sitting there in it's plastic lined, vacuum pouch when I got home from work. After opening the Mattress shipment it needed to sit for a full 24 hours to fully expand to it's original size. It reminded me of those little toys you used to get when you where a kid where you placed them in water and they grew to 10 times their original size.
Anyway ... I couldn't be more satisfied with this purchase. The feel of the memory foam vs. a spring mattress is definitely unique but I don't think I'll ever want to go back to sleeping on a regular mattress again.