I think, at the very least, DOMESTIC absentee ballots should be allowed. If someone must travel abroad on election day, why can't s/he vote? If someone is homebound (by, for example, illness or physical disability), why shouldn't s/he be allowed to vote? I think allowing Israelis who live abroad the democratic right to vote (especially since some of them actually pay Israeli taxes) seems fair. But certainly those living here who can't make it to the polls for whatever reason (even laziness!) should be allowed to vote.
One student killed, three wounded at Arizona campus during fight (a)
from the article: Move for absentee voting prompts fire across the political spectrum