Default application. How to?

["[KS]" <lists04@fastmail.fm>]

Hi,

I have been trying to find a way to set one browser to be default one on 
my Debian Sid box. But till now haven't found any "work for all" cases 
solution. Does anyone know how to go about doing this?

I want an http:// link from various applications like Thunderbird, Nvu, 
Acrobat Reader, etc open in the "default browser" irrespective of the 
browser being running or not.

Also, how can similar functionality be achieved for mailto: links? For 
example, I use Thunderbird, so clicking on mailto: links should open 
Thunderbird(for different applications). Right now nothing happens.

Thanks.
/KS