I ended up getting that "Not really a flashcart" Datel DS flashcart, and I loaded it up with DSOrganize, a homebrew "OS"

https://www.gamebrew.org/wiki/DSOrganize

It had a semi functional web browser included, without the RAM expansion cart! It somehow managed to browse most simple web pages on the inbuilt RAM from a hobbyist!

It also had an IRC client, and that was my introduction to IRC

And Internet Radio! You could point it at an internet radio station with a special "playlist" file that had a URL, so that's how I helped feed my Technobase.fm addiction at the time, before smartphones. I could carry around my DS and listen to internet radio!