Today I decided to throw together an ugly little script that allows you to search swedish phone numbers from a terminal. It's basically just a tiny python script that uses the public API available from 118100 at utveckling.118100.se.
Just download and unpack the tarball and you should be ready to go (you'll need to have lxml though).
The functionality of the script is sort of limited since the public API is also quite limited, the only arguments except the search string right now are -x to display the raw XML returned by the API and -s for specifying the number of results to return. There is a "secret" feature though, if you search for a phone number and use the -x flag you can find companies as well (it won't work without the -x flag since I stripped out the code for parsing company records).
If you actually end up using the script for something then I'd love to hear from you.
Update 2010-07-21:I've uploaded an updated version of the script with a README file (in swedish) that's available here.