I went on my first group ride last week with a women's group, and decided to wear my Camelbak because that's wear I carry all my stuff, and I feel naked without it. Before I got there, I wondered if I would look geeky, like a mountain biker out of place. To my surprise, every woman was wearing a Camelbak of some sort. Of course, this is Phoenix, and a couple water bottles just won't cut it in this heat. For longer rides, I usually fill my bladder to the rim, and also take a bottle of Gatorade on the bike. I don't have a cell phone, but I carry a portable handheld ham radio, which is a bit larger and heavier. It usually goes in the Camelbak, although when I ride where there's little traffic, I hook it onto the front shoulder strap. That makes it a little easier/quicker to access when my husband calls. However, he knows to give me a couple minutes when the radio is on the back.