Good idea, however you will need to consider;
- how to allocate and manage bandwidth and total usage to each client
- how to bill each client based on their usage, otherwise you will get the hogs
- how to solve the hidden node problem which will cripple a network with more than 5 or 6 clients connected
All the answers are on the internet, happy researching :wink:
Good starting point
http://www.wafreenet.org/