We are going to try the IRS service
Can we send 49 letters to them and then another couple batches of 49 without being charged?

What other services including locator services , websites, etc... are out there?
thanks
Laxy

You may find value in: http://www.ssa.gov/foia/html/ltrfwding.htm

Now watch Donkey Kong add his stupid picture to the gallery.

I've had some success with Accurint. Not sure how much they charge, because I was with a large company at the time, so I'm sure we got a volume discount.

Our clients have had pretty good luck with the Berwyn Group. I thought their pricing was very reasonable.

https://www.berwyngroup.com/db/Home.asp

Plus their logo looks like your avitar which I'm sure is highly significant...

Not quite. It's 49 or fewer in a 12-month period.

This is the <50 program: http://www.irs.gov/retirement/article/0,,id=110139,00.html

This is the 50+ program: http://www.irs.gov/retirement/article/0,,id=110142,00.html

Is the IRS program only for terminating plans?

No. Not "for plans" per se.
Think of it generically, as a letter forwarding program, rather than a lost participant program.

But you need a compelling reason to use the service. You just can't use it to track down a dead-beat ex-wife or a long-lost pal from first grade. (Of course, locating someone for benefits purposes is a compelling reason)