Something that I've been doing is using my iPad as a lightbox -- I have the flashlight app which makes the screen white (and it will stay on indefinitely) and with my loupe and negative sheets it works great.
My favorite thing is to go where I've never been. D. Arbus
You can do the lightbox thing with a digital P&S or DSLR - just take a pic of a white sheet of paper. Voila - instant lightbox! And when you run the batteries down, well hey, you still have a real camera to take photos with!
Shoot more film.
There are eight ways to put a slide into a projector tray. Seven of them are wrong.
Ive also been doing this for awhile now too, but I use a free sbsettings toggle from cydia to enable inverted colors. It is much easier to do this if your negs are sleeved and on a light box than hanging free. You can also rest your phone camera on a loupe for a magnified view.
Sometimes when I do want a quick look while drying, i max out the brightness of the screen (another sbsettings toggle), and open up the web browser and a new blank tab. This gives me a bright white screen to put behind the negs that are hung up to view them quickly.