Attaching tactical/military pouches to bicycles is nothing new but I have found that Blue Force Gear’s Utility Pouches with Helium Whisper backing work particularly well. They are very lightweight by design and the Helium Whisper backing has a rubbery texture that, when woven tight, really grips the bike and prevents the pouch from moving.

The image above shows a BFG Small Utility Pouch attached to the handlebar of a mountain bike so that the pouch rests on the stem. The picture makes it appear quite large but it actually fits in the space very well. It is a great place to store some bike tools, a pair of gloves, a spare tube, and any other items you may need.
I have also used the same pouch attached to the support members of a rear bike rack and attached to the frame in various ways. Basically, as long as you can be a little creative with how you weave the straps, you can find a ton of ways to mount these pouches to a bike.
I use this Small Utility Pouch because I just happen to have a couple in my gear box. My next step is to order some of the larger pouches to see how I might be able to use them. For instance, the Medium Horizontal Utility Pouch or Large Utility Pouch might work well as a front mounted handlebar bag.