Is there a special url for sharing to Facebook and Twitter for mobile? Or are they the same as those from websites?
Using
Your sharing implementation should be the same and should work so long as your mobile users have devices capable or rendering JavaScript. Otherwise you can use each platforms' API url to share inside a link, the only problem is the callback redirects them either to Twitter or Facebook and they'll have to manually return to your site. The links are as below:
Sharing on Facebook:
http://m.facebook.com/sharer.php?u=t=
For example:
http://m.facebook.com/sharer.php?u=http://www.google.com
Updating status on Twitter:
http://mobile.twitter.com/home?status=