Erssel,
I'm also neither Bob nor a lawyer, but my understanding is that you'd own the copyright on the photo, but that isn't sufficient to display the photo (or derived works, such as a scrolled portrait) publicly.
As Kevin says, the Rich and Famous are particular about their publicity, and corporations (such as NASCAR) are particular about their trademarks.
Additionally, you really can't use images of normal folks without their permission - photographers generally have their subjects sign a model release before they show the pictures publicly. You're not likely to get in trouble for it (Joe Average is less likely to care than Henrietta Hollywood), but it's a bit of an invasion of privacy.
None of this applies for news purposes (including tabloids

), but does for most other public showings.
If you use a photo you took as a base (so you own the copyright) and modify it so that the subject isn't obvious (photoshop out trademarks, cut out a featureless silhouette, etc.) then you shouldn't have any problems.
Model release - Wikipedia, the free encyclopedia
--Rob