Ideas

This has potential. Maybe you can flesh it out some?

potential..

the tax aspect seems prohibitively complex, but maybe we will be at a sales tax or flat tax in a few years, so that wont matter....
liability is another issue as well.

also it seems you will have a tricky time getting customers. But if you can proliferate the service, I think you will have a winner.

My advice, start in a very dense and prosperous place, such as manhatten.

There is a lot of logistical overhead involved in renting everything. For things like apartments, you need cleaning services and maintenance visits after every rental. For more portable stuff like bikes or cars, you need to match up the renter with the owner. I might be willing to rent my bike on off days, but I'm not going to want to store it at your rental warehouse or make the effort to drop it off when a renter needs it.

You'd also have insurance issues both for intentional misuse and accidents. Many people are automatically covered for car rentals, and most rental property owners have insurance specifically to cover that situation, but you'd need some mechanism for protecting the more mundane items.

None of these are deal-breakers. Just things to think about in working out the details.

We actually had a similar idea that we were going to post, ineeda.com, ihavea.com. Renting things can be difficult to facilitate but if it is handled like craigs list where the responsibility lands on the lendee and lendor, it should be all right.

Let us know if you need any ideas.

Do it up.

Search CH, I know I had read this idea before... I think it was by someone that worked for CH

Regarding apartments, I'm worried about issues such as trust. If you verify the bona fides of a renter and have a written agreement, you have as much paper work as any other rental. If not - you're lucky if you only find your place has been left a mess.