With a little sewing you could create a tunnel strap on the nice fleece cover of the milspec canteen assembly and slide it onto the strap of your fanny pack. Alternatively there is a decent titanium tumbler with folding handles that fits nicely around the bottom of a sports drink bottle. weighs almost nothing - costs decidedly something. I believe I got it from EMS retail - mfg'd by MSR in the titan line. Holds ~20oz fluid.<br><br>one online source found through google - there were a bunch so this is just the first so that you can see it.<br><br><br>MSR Titan Cup