Just found THESE (clicky clicky) at my local office supplies store.
Already using them to keep my straps/whoopies unraveling in my pack, as well as to hang things off the ridgeline.
I am not affiliated with any of these companies but found these simple and clever. I bet the crowd here can find another dozen uses easily.
($5 for 10 of 'em in mixed sizes at Thinkgeek (clicky clicky) )