The map data is free for registered users to download for their own personal use - unlike some governments that use taxpayers money to collect the data then *sell* it for ridiculous fees (Ordanance Survey, I'm talking about you!). The only thing I ask in return is that any updated maps are uploaded back to the project.
There are some restrictions as the whole data set is 36Gb, if everyone downloaded everything I'd have to sell a kidney to pay the bandwidth charges. Registered users can download FIVE maps per day, members can download FIFTY as they've contributed to costs.
To select a map enter a latitude/longitude and click the download button. The maps are in polish (mp) format and zipped to save bandwidth.
Enter a decimal lat/long to select a map, ie: 12.324234, -56.345435
I recommend using GPSMapEdit to edit these maps. You can download the latest shareware version from here. If you register this software you can work with satellite images and do loads of other stuff, well worth the price.
Work has also started on a free map editor to work directly with the project but thats likely to take a while. News on that can be found here, if you have Java skills and some free time to help code it we could use your help.