I have a wide range of scientific and technical knowledge, and it can come in very handy.
My favorite software package of all time is Wolfram Research's Mathematica. It does computer algebra, graphics, and similar sorts of things.
One of my hobbies is a rather strange one: working out various mathematical and mathematical-physics results with Mathematica. I have created a sizable number of Mathematica notebooks on such subjects, ranging from Lie algebras to differential geometry to orbit mechanics.
http://lpetrich.org/Science/ -- that page links to various webpages that I have created. They include:
A symmetry demo that works on pictures of various organisms, from cats to jellyfish to flowers. Rotate and reflect copies of them, copies overlaid onto their originals.
Color-blindness simulators, including Photoshop and GIMP channel-mixer matrix files, a standalone app written in Java, and a version that works on webpages in one's web browser (currently only works in Firefox).
Some Mathematica notebooks with various mathematics results, like Lie algebras (for Grand Unified Theories and the like) and construction of mathematical entities like quaternions and octonions.
Work Terms
I am using awake most of the day (US Pacific Time) and much of the night. However, I have problems sleeping, and that can make my hours irregular.
I'm most conveniently paid through PayPal: paypal.com
My favorite kind of online communication is real-time text chat / instant messaging. It has the immediacy of telephone conversation with the persistence and easy access of writing. I also like messageboards/forums, and I'm one of the administrators of one, doing mainly system duties. I also do e-mail, of course. However, I don't have a working land-line telephone with me, and I don't have a mobile phone. For voice conversation, I'd prefer some Internet telephony like Skype.