She is charging $30/hr, and is also going to tech tradeshows. That too is an interesting angle, although not very unique. I have been to many tradeshows, and have seen a lot of hot-to-semi-hot girls walking around clad in various T-shirts.

If your target market is mid-20's guys, I think this angle could have some merit. If your target market is the "average" consumer or corporation, I'm not sure how much marketshare you are really going to get from a pair of tits or an ass logo.

I think the real angle for these girls is to do a "Social Media Starter Kit". This T-Shirt girl would be better off not just "mentioning" the product and flickr and twitter, but setting up accounts for these companies and "seeding" the social media sites, then handing the keys over with a bit of training to the organizations. Basically teach the companies that want to leverage social media but don't know where to start how to jump in.

That would likely be a week-long effort, and she could probably charge $3000/wk, based on what I've seen from the current crop of wanna-be SEO hacks.