I would like somebody to invent a pill which contained a mosquito repellent that was harmless to us yet would release its ingredient in our sweat and natural odour thus becoming the best mozzie repellent since the electric fan.
I once had an idea for an instant freezer which would have the reverse effect of a microwave but by placing items to be frozen in a conventional freezer an hour or so before you needed them would be a better idea.
It would also be great to see a cigarette substitute that cleaned your lungs and a 'live' as it happens version of Google Earth that had infinate clarity.
What would you like to see invented? Cures for cancer, AIDS, the common cold etc.. all go without saying, and I'm not sure if medicine is invented anyway, more discovered.