You could make one... Go get a nylon belt piece and buckle from a craft store or even REI/other sporting goods store may have multi purpose straps with clips. I got one of these to keep my sleeping pad rolled tight for cheap at REI.
Backpack waist strap. Trouser belt that is long enough to get through. Nylon web belt for convertible type pants. Borrow one from Mumbles. Get one at Sportsman's (Outdoor Outfitter), Kitsap Sports, Wal-Mart or the like.
after several years of dicking around with homemade contraptions that worked pretty good, i just bought the orvis basket.
worth every penny. seriously. plus its orvis brand. clearly leads to more hookups and more streamside swagger. when i was at dash point people walked me to the school of fish, rubbed my shoulders down, stretched my line and removed any and all foliage from my fly because i was fresh to death in the flyest gear.