Hi Caleb, welcome to the Cameralabs forums!
As far as I know, there's no AC adapter accessory for the E-510. I didn't mention this as a shortcoming in my review as it wouldn't bother as many people as some other aspects, such as the viewfinder or manual focusing.
If you're after Live View and a DC input option from a DSLR, I'd wait for the highly anticipated Olympus pro DSLR. Its predecessor the E1 has a DC input, so it's likely to be present on the new model.
We're only speculating now, but judging from the prototype photos, the new model will have Live View AND a flip out screen, which I'd imagine would be even better-suited to your style of photography.
So fingers-crossed there's an official announcement later this year!
Our preview is here:
http://www.cameralabs.com/analysis/Olym ... age3.shtml