well, if it were truly straight, no, because you wouldn't follow the curvature of the earth... otherwise, yes, you should end up at your starting point eventually.
Yes! well, in back of it any way..... you might need a few plans or boats....(or submarines!) and hop some fences, and i hope Area 51 isn't in your path!
EDIT: hm, i read some other answers... i guess maybe you'd be a few yards away from your house! lol!