I don't have AA, can an ATI Radeon 9550 graphics card enable Anti-Aliasing for Blockland?
A Radeon 9550 would probably have troubles doing high anti-aliasing, but 4x might be fine.
You need to have a non-integrated graphics chip. It can't be Intel or whatever vague integrated brand. Nvidia and ATI are the only two GPU manufacturers who have control panels with their graphics card drivers. Simply open up your graphics control panel, find something that looks vaguely similar to "application settings", add Blockland and make Blockland have the desired amount of anti-aliasing. The highest is 16xQ which is what most people here use, but I only recommend going that high if you have a higher end graphics card, otherwise I recommend you setting it to 4x or 8x.