Many people receiving the calls are complaining to the (innocent) Dem candidate.

If the message says they are calling on behalf of a Democrat, don't assume this is true. The robo-callers are often not identifying their sponsors until the end of the call. (Which is against FCC rules).
If it takes you more than ten seconds to identify who the call is from (not who the call is about), be suspicious.
If the caller ID is from out of state be suspicious.
If they call at odd hours, be supsicious.
If they call back on you after you hang up, be suspicious. This is also against the FCC rules. (The goal is to make people think they are being harassed by the Democrats, and piss them off enough to change their votes.)
If the message fails to leave a callback number, this is illegal.
If the message tells you that if you voted in the primary, you do not need to vote again on Tuesday, This is a LIE.
IF THE MESSAGE TELLS YOU YOUR POLLING PLACE HAS CHANGED, verify this yourself by calling your County's Board of Election. Directory, here:
http://www.elections.state.ny.us/portal/page?_pageid=35,1,35_8677:35_8685&_dad=portal&_schema=PORTAL

NY-19, NY-20, NY-24, and NY-25 are four of the districts where voters are reporting this dirty trick.
Check here for updates:
http://www.dailykos.com/story/2006/11/6/02926/3087

Try to get them on tape, especially video tape, if you are subjected to harrassment or deception.
Report any illegal robocalling here:
http://www.dailykos.com/story/2006/11/6/142133/889

And don't forget to vote tomorrow.

Adam