I replied to this back in the day, but I now have a different job and they have an interesting 401k match. They will contribute up to a certain percentage of the total amount you contribute. The match is contributed in a lump sum at the beginning of the following year, and you don't know how much they'll match until they're about to do it. Last year it was 35%, the year before was 25%. Meaning if I'd contributed the full $17,500 they would've contributed $6,125. It's immediately vested.
It's a pretty sweet deal, I think I'll be a little shy of the max at $14k or so this year, so that'll be just under $5k match, or more if they up the percentage again.