If you are having trouble connecting to the Internet using your Nokia N900 as a 3G modem with Network Manager, you should check those bugs.
(In short: bug fixed upstream, but affecting the version in Debian. Using the package from Ubuntu works.)
Seen on The Ruby Reflector (a blog aggregator for the Ruby community):
Under no circumstance should you install Ruby, Rubygems or any Ruby-related packages from apt-get. This system is out-dated and leads to major headaches. Avoid it for Ruby-related packages. We do Ruby, we know what’s best. Trust us.
(source)
It’s always nice to see people appreciate your work. :-)
apt-get install mpich2/experimental