Given the rapid popularity of Twitter, more and more people are finding ways to cash in on the powerful micro-blogging site.

Tweexchange, a new startup, allows you to buy, sell or exchange your user name for a price - a service that is similar to buying domain names.

Selling “free” Twitter names is apparently ‘against Twitter rules’, but it’s unclear as to how and if Twitter is enforcing this rule.

The interest in Twitter names is hot, said Agranoff, a noted blogger and the founder of the company.

To build Tweexchange, Agranoff posted the project idea on his employer's website and soon after receiving several bids, awarded the project to a developer who knew the Twitter API. Agranoff then posted and awarded a second project to a graphic designer. The bi-awarded team created Tweexchange in less than a week and all for under $1,000.

It was that easy, Agranoff said. I had the idea to build Tweexchange on a Friday, posted the projects to VOIS to bring my vision to reality and within a week I had the site up running and looking good.