Entering Competitions
So, you want something for nothing? Well this is a good start, an agregator of links to competition sites sorted by when they end, comps-online. Thanks to the lovely people at mozilla (and opera I'm told) you can use tabbed browsing with it too, so you can open all the comps from a day and then go though and do them all, well that's what I do anyways.
There is a offline version too if you feel inclined to go though and write out loads of postcards. And it all comes from the comps.org database, which you can help to fill using this bookmarklet Add Comp (instruction on how to use bookmarklet).
Its pretty easy, you find a competition page and hit the bookmarklet, it then opens you a pop-up where you can fill in information about the competition, and quite importantly, the closing date of the comp. And if you're already doing the competitions then it won't take but a few seconds longer.