This script draws a simple real-size, non-obtrusive minimap on your radar. Not just an image, but a dynamic map moving with you. It displays not only walls, but also obstacles, toxic tiles and water.

Performance
I just saw someone has done such a thing before ( Radar Minimap (29)). However, this one is better of course

Like the other script, the drawn minimap is created from separate images. Since the radar has a radius of 12.5 tiles, some π × 12.5² ≈ 491 images would have to be loaded per player. For a server with 16 players that would mean 7854 images, with 32 players fifteen and a half thousand, which would result in a definite crash on the average computer.

This script, however, drew only 24 images at once during some testing (for a single player of course), with (judging from screenshots) even better accuracy (but that's up to you to test). Other maps, especially those with a lot of water or toxic stuff, might need more images.

Now, 24 images is still a lot, that's true, but it makes playing with at least ten players perfectly possible, even on a crappy laptop like mine. Just imagine what a good server could do!

Caching
Instead of iterating over the entire map every time new map is loaded, the tile properties are cached so they can be loaded quickly the next time. They are saved as a Lua table ({{0,0,1,[0]=1},{1,0,0,[0]=2}}) so they can be loaded faster.

Aesthetics
Now, this minimap is definitely not the most beautiful (it cuts off tiles at the edge due to the radar's round shape), but it works like a charm. With an eye on performance, I decided not to implement any nice rounded corners or other nice stuff such as smooth movement. You might want to change some colours though, you can find the tile properties at lines 162-172.

Now, I hope you find some legit uses for this (don't use my awesome *ugh* technique for cheating). Should you find any better vectorization techniques, please let me know