Not sure if this has been covered but I wanted to install Opera 4.1 and could only get the Jad and Jar files. You cannot install these using install desktop manage as they are supposed to be installed direct from your phone. But if like my I don't have a blackberry data plan so my default browser will not work so I cannot download
So instead I used the media manager and copied the files over to my blackberry.
I then clicked on Media - click on wheel and choose Explore I then found the jar file I copied over and opened it. Agreed to the warnings etc and it installed fine and works a great
