There have been a number of conflicting reports about obtaining a tourist visa for Uganda on-line before travel. The good news is that, according to the Ministry of Internal Affairs, visitors to Uganda DO NOT need to apply online before arrival. There is a plan to make this compulsory and you can go to their website to do so but there is no date confirmed as to when this will become compulsory.
Some travellers have said that the queue at the airport is shorter if you have already registered on-line. Some have said it was longer!
In more good news, the price of a single entry tourist visa has been cut in half! It is now $50.