Out of curiosity what do you do? If you don't want to share that's fine, but I also wish to do the same however have not found something to solve/make yet.
Literally the most boring thing you would ever think of which has tons of competitors. I sell it to big companies who don't mind spending $1K/year on it (h/t to Joel on software for this tip)
If you want to do it, then find some product that exists, that you like, copy and tweak.