Overclock Intelligence Agency takes a look at the OCZ 8GB Mega-Kart:

But frankly, I found the Mega-Kart to be too darn slow. When copying lots of files in my tests, the write speed slowed down to a turtle's pace, only 0.3MB/s. It fared no better when I ran my weekly backup (which normally takes ~45min to copy and verify on DVD+RW) and that 4"GB of data of mine took over 4 hours to copy, never mind running a verify afterwards. Forget about downloading those files quickly on your way out the door or performing a speedy file and settings transfer from one computer to another. You better plan on starting your save way beforehand unless you've got a lot of time to kill. Once you've got your data on the Mega-Kart, if most of it is fairly static you could probably get by okay with just doing an incremental backup, or only copying over those files that have changed recently.

Price-wise I found the OCZ Mega-Kart comparable to other manufacturer's 8GB drives available on the market, if not slightly cheaper, especially with the rebates OCZ is currently offering on many of their flash drives. It came to only $130 at one popular online retailer, when other brands are going for $20 to $30 more. The 16GB version is more than double the price, well over the $300 mark, however from what I could tell it's one of only a handful of 16GB flash drives out right now. Unless you absolutely need the space however I suggest you check out OCZ's Rally or Rally 2 line of performance flash drives, I guarantee you'll be much more pleased with the speed.