I'll be changing both first and last names. The current one is just... annoying, because people always get it wrong, and my father isn't around any more to mind my dropping it. I'll be taking one from my mother's side of the family, not because I was fond of her (so not!!), but because I think I'd have liked my great-grandfather a lot -- and it's a super easy name.
One does need to notify creditors, utilities, banks, etc., and get the deed changed on any property one owns. In my state, if you own property, you need to bring the deed with you to your name change hearing.
I asked the folks at my bank about it, and they said it's no problem to change the name on bank accounts. All they need is a copy of the court order and to record your new signature; the account numbers will stay the same.