One business model that I've seen - which AFAIK has been successful - branded itself as a "community" bike shop. The shop has some elements of a normal LBS: they employ mechanics and do full-service repairs, sell bikes (mostly used, mostly geared toward the family/hybrid/commuter market) and accessories (again, geared toward that market.)
They also offer classes (some free, mostly paid) and a DIY space where people can come in and use the tools (it costs money per hour). It's not quite a tool rental service, but provides access to shop tools in a way that's different from the usual co-op model.
Personally, I've never used this kind of service. My guys and gals at the LBS will usually hook me up with stuff like setting a crown race or cutting spokes; for normal repairs, it's worked out cheaper to just buy tools than to rent a space by the hour.