I bought myself a set of battery operated pumpkin carving tools this year.  There is a carving blade, etching tool, drill, plus one of those manual Pumpkin Masters type drills and a manual tracing wheel.  The tracing wheel does a great job of transferring patterns to the surface of the pumpkin without much effort.  However, you can only really use it on large, relatively straight or slightly curved areas.  On very detailed areas the Pumpkin Masters type pattern poker is a much better bet.  The blade does a good job in carving, but only if you have your pumpkin's walls scraped to no more than an inch thick.  Anything thicker and the blade tends to bog down a bit.  Not bad though, considering that the thing is battery operated.  I can't comment on the etching tool as I didn't do any etching although I suspect that it does a decent job.  Control is a factor as it is with any carving job; it is easier to get carried away when you aren't manually sawing at the pumpkin so a bit more care needs to be exercised when using these tools than is necessary when using manual tools.