Some mini wireless finger trackballs would be better for surfing the internet with your mobile in bed .... isn't it ?.... It should wireless AND mini AND handy AND ergonomic AND good sensitive AND 'rugged' AND something like a ring around your finger AND ... so on... 
Here are some i found on the net, but not quit what i 'suggested' here above ... :
Mouse or trackball?
This super-mobile hand trackball might save you a lot of space | TechCrunch
Here are some i found on the net, but not quit what i 'suggested' here above ... :
Mouse or trackball?
This super-mobile hand trackball might save you a lot of space | TechCrunch