Christopher Kalafarski , Jun 20, 2009; 10:14 a.m.
Maybe I'm reading your post wrong, but when you say "the" software, it makes me think you're looking for some specific software package called "Sports Collage." As I'd never heard of that, I did some googling, and I'm still not sure what you're talking about. I saw some services that make sport collages, so if you are simply looking for that, the answer in terms of software is undoubtedly Photoshop and some hard work (masking, etc). Regarding labs, I don't think there are going to too many printers that do this kind of thing; like I said I saw some services online specifically for creating sports collages (though to be honest most looked very bad). I'm guessing any "really cool" examples you've seen have been custom jobs by an actual graphic designer, so if you're wanting to get one great collage done for yourself or someone you know, you should look into that route.