Yeah the demoscene jumps out as a good candidate to represent "creative 'useless' programs". :)

I make a few demos, but my personal favourite was this 4k (windows executable less than 4096 bytes):

https://www.youtube.com/watch?v=sBcwQCBpEiE

It uses all the fancy compressing linker tech (called crinkler) along with a tiny music player and a glsl raymarcher.

I tried to download it but all I get is virus warnings now... I guess malware devs also like crinkler. :(