Geez, the words "fanny pack" don't sound cool at all, and believe me, wearing one is certainly not cool, either.
However, I had to give myself a bigger butt than usual wearing this because a few weeks ago, someone took my water bottle while I was doing a long run. I had hidden it behind a tree, and when I came back for it around mile 6 (of 10), it was gone. Defeated, I had to cut my run short.
I picked this up at Sport Chalet. I am a fan of JanSport because I used to envy all the kids who had JanSport backpacks that seemed to last forever and ever without breaking (plus they looked cool), while my ghetto, un-cute, boyish, hand-me-down Chinatown backpacks would develop holes that would have to be sewn up over and over again. On that note, don't get me started on "Adidos" items...
Anyway, now that I am older, there was some glee associated with the purchase of a JanSport item. I was finally able to give this a spin this morning on an 11-mile run, and I think it served its purpose, keeping my cell phone, mace, iPod, and water bottle with me the whole time without a significant effect on running. I'd say the only noticeable things were a slight noise from the zippers, pre-chafing because I didn't bother to adjust it properly (it was 6 am...), and slight up-and-down movement that also might be related to improper adjustment.
It is VERY nice to be able to drink water when I want. I'm sure it will also come in handy on longer runs when gels and such are needed. Still, I must say that this morning's 60-degree weather shrank my need for water significantly. It was just a very nice run in very nice weather.
Another upside to having an expanded butt is that I look even more atrocious on the road, which might decrease my need for mace. (I'm not taking any chances, though.)