I have this one:http://www.teamestrogen.com/prodNN_4490N.html

You could carry the lock in the pocket or the gel sleeve. I usually put my cell phone in the gel sleeve and stuff blocks, TP, keys, and chapstick in the pocket. Plus you can put a light jacket in the compression band thingy. I love mine.

I run with it all the time. The waistbelt is kind of stretchy, which is nice. The Ultimate Direction ones don't have that feature (or at least they didn't used to). Martha complains about that all the time. I keep telling her to get the Nathan.