Astute observers of the ESPN.com fantasy sports frontpage will notice an ad for Fanball’s salary-cap football, an ad that links to an ESPN affiliate site for the Fanball game.

There’s no mention of ESPN on Fanball’s landing page for the game, so it appears that the two sides have merely partnered up to create an avenue from ESPN’s high traffic into Fanball’s pay ($39.95) game.

More importantly, no game in the actual ESPN fantasy lineup appears to charge users. Could we be seeing some change in philosophy from the “worldwide leader”? ESPN offered its own salary-cap football game last season, Gridiron Challenge, but that contest doesn’t appear on the 2009 docket.

“We’re always looking for new ways to engage fans and develop new game experiences,” ESPN’s Nate Ravitz told FSB.com. “[We] are looking at this as an opportunity to learn about the demand for this style of game without any specific expectations.”

If this is somewhat of a test case, we’ll have to see what follows.