I was thinking of pulling together some of my favorite Web 2.0 sites and tools that could be used to run and market your business. Well, I can't get much more comprehensive than this...259 pages of Web 2.0 sites. The cover says these are social networking sites, but the list is much more broad than that. Just do a search for 'invoice' and you'll find 30 sites, or 'chat' (167 results). I'm becoming more and more convinced you could run an entire company on free tools. Question is, are you willing to take the risk....as most of these companies are unprofitable and will run out of VC money at some point.