Free Banner and Traffic Exchanges

BlogExplosion
This is basicallly a click exchange for blogs. You surf other people's blogs and they surf yours. The exchange rate changes from time to time so we can't list it here.

w3exit
Popunder traffic exchange targeted to web development sites.

LinkBuddies
One of the oldest and most stable link swapping systems. Swap text links, banners, or buttons.

WebmasterQuest Traffic Exchange
Traffic exchange program for Webmasters. You look at other people's sites and they look at yours. Several different ways to earn credits.

ExitExchange
An alternative to banner exchanges. When users leave your Web site, a new browser is opened that includes another site. Your site appears in the exit pages on other sites. A lot of pop unders are blocked these days, so this isn't as effective as it used to be.