I took the bull by the horns and dug down to it and installed a splice in it this weekend. I had a hole in the ground that was big enough to bury a horse! Sure enough, the break was right up next to a root for some vibernum bushes growing nearby. I used two of the rubber boot-type splices that use the allen bolts to clamp down. Apparently these have some type of glue/sealant inside of them that bonds to the insulation - all you do is strip back the insulation, shove the wire into the boot, and tighten down the allen heads. There are two caps that cover the allen heads. A couple of the electricians that I talked to recommended them - said they were easier and more trouble free than the heat shrink type. I had to splice in a two-foot section of cable. For good measure, I cut a piece of plastic conduit open and slipped it over the spliced area, hopefully to protect it somewhat from further root intrusion. Jcap, I did see what you are talking about with the corrosion working its way up the wire. As you mentioned, I am considering this a temporary repair. I am going to pursue the overhead hookup, and relocate the meter while I am at it. I just had to get our service back before the holidays.
Thanks for all the advice. I guess I saved several hundred dollars by doing it myself. Unfortunately, Santa still might not bring me those Merlins, since it is very likely that I will be spending some $$$ to switch to overhead in the near future. Oh well, I'll be stuck with a slow boat for a while longer, but at least I have hot water!