prefix

For a project of mine, I'm looking for a solution to the following problem. I want to show for a path prefix, a mobile version of my site. So if someone calls http://www.mysite.de/m/ he will see the mobile portal. On http://www.mysite.de/ he will see the normal site. Unfortunately I have not found any possibility to create own path prefixes.

Do you have any ideas?

Is it possible to negotiate language (user preferences, browser settings) for every url without prefixing the path or domain? The site I'm building uses Drupal for Facebook, a.k.a. DFF, to integrate with Facebook. Facebook requires a single callback base URL from which all paths are built. DFF handles this with a url looking something like www.example.com/fb_cb/12345. Drupal's language handling breaks this by inserting the language prefix before DFF's callback, e.g.

Finns det någon som har ett tips på hur man i ett CCK-fält automatiskt lägger till ett prefix eller suffix?

Exempel: Ett fält där man anger längd och då läggs mm till i värdet?