One of the things people talking about reputation seem to miss is how easy it is to establish that base level of reputation. A couple of decent talks at local user groups will be enough in most tech areas that have job openings for employers and people with other opportunities to start querying you before they move onto more blanket searches.
On top of this I really dislike the argument that the skills are transferable from a big company to a small one easily. It seems like a much better argument for going towards something like a small-medium company. In the web space I'd suggest that the plethora of 10-40 person bespoke web dev shops that float around are a very good option for gaining broad skills and being less risky than startups.
People who are interested in startups should join something that looks pretty similar to a startup. People who are interested in making 10 million dollars should join a big company and live cheaply.