We have a hookup (MrsC likes her camping 'comfortable' and, as I get older, I find I agree more and more!).
Used it for the first time in France last year. We were running a small kettle off it, as well as using it to recharge the iPod, the phones, the cameras, the laptop...
We intend to get a fridge (again a very small one) next, but as we're currently not planning a major camping holiday this year that may well have to wait.
Recommended if you're in the 'luxurious' end of the camping spectrum
S