adultfriendfinder.com has worked for me. Although they do have a free membership it is very limited on what you can do. You do have access to the instant messenger and are allowed 5 messages a day and you can goto members that are streaming video for free and possibly chat with them online the 5 messages applies to this area as well. They do allow you to use a gift card to pay for membership, if you need to be discrete about being a member. I think the lowest amount they accept for gift card payment is 10.00 and that would get you 9 days of gold membership. Basically 1 day less than the dollar amount used.
But i have not found anything better out there that is free.

Unfortunately there are none. Men have to pay to join. I have had some success on Seeking Arrangements...