I use my own personal web hosting. There are free pic hosts available such as www.imageshack.us, www.photobucket.com, and www.flickr.com who all allow hot-linking, I believe.

And I use the streets rather than the bike path just because I think it's faster. The east-side bike path would be a longer distance for me and I'd have to deal with more pedestrians. That's just my opinion, though.. I could be way off as I haven't used it heavily.