If you are a Last.fm user then this application which is currently in development could be of interest to you. Last.fm Mobile in its Pocket PC version has scrobbling and radio functionality, and the Smartphone version is limited to scrobbling from Windows Media Player - but it works perfectly.

In case you're not aware, Last.fm is a UK-based internet radio and music community website, founded in 2002. It is the world's largest social music platform with over 20 million active users based in more than 232 countries. On 30 May 2007, CBS Interactive acquired Last.fm for £140m (US$280m), making Last.fm the largest European Web 2.0 purchase to date.

Using a unique music recommendation system known as "Audioscrobbler", Last.fm builds a detailed profile of each user's musical taste by recording details of all the songs the user listens to, either on the streamed radio stations or on the user's computer or portable music device.

This information is transferred to Last.fm's database ("scrobbled") via a plug-in installed into the user's music player. The profile data is displayed on a personal web page. The site offers numerous social networking features and can recommend and play artists similar to the user's favourites.