Freelance writer for Web 2.0 site

We are launching a new site for a mobile app and looking for a fun, creative writer to write copy for the new website (i.e "features", "how it works", etc..), that will encourage potential clients to signup for an account while at the same time not confusing them with too much verbiage or technical details. Style of writing that we are looking for is fun, hip, but also professional. We would also be looking for some insight on flow and usability of the site.