You should not have to log in to anything to download Inkscape (though inkscape.org loads just fine for me, so maybe you are having a different problem?); just grab a binary from sourceforge.net/projects/inkscape/files/inkscape/0.48.5/ if using 32 bit Windows, from a repository with apt or yum or whatever if using Linux, and doubtless Mac has something similar to one of the two.
For a quicker response in the future, try irc://irc.freenode.net#inkscape (although you still have to be willing to help those there help you).