automated submission to social bookmarking sites

I need a c# program which will automatically submit to 3 different social bookmarking sites. functions should be provided to submit to the following sites (this is possible since none have captchas, we just need an automated form filler). In addition 3 accounts with passwords should be provided on each site for testing. It should be possible to either submit with a given account or use a random account from the available accounts. All accounts (username/password) must be stored in xml. functions should also be supplied to add an account to the list. The social bookmarking sites of interest are: delirious delicious furl LINQ must be used to manipulate XML, this is much easier to code and understand.