I am in the Bay area, and I'm interested in all local tech conferences. Seems like if I search for SF, I only see conferences in that city. What would be useful is to gather commutable geos together. When I was on the east coast, NY, NJ, CT and MA conferences were all reachable in a day trip, which is why that was my region of interest.
I think someone did this for hackathons too but not sure if that died off. Another idea is to link to previous iterations of conferences.
Final thought .. you could mine ACM/IEEE conferences .. those are tech-relevant.
For example, ACM CHI has a huge expo for demos and tech companies. IEEE/ACM ICSE has an industry track (now known as Software Engineering in Practice).
A calendar with a tag cloud that can be toggled.
A world map with the same tag cloud.
Work backwards and make it into an archive of-
a conference about conferences.
1. Create website that aggregates something tech event
2. Drive traffic to it through SEO and by utilizing the FOMO
3. Create a conference about tech conferences and have an instant audience
It's such a dumb idea it <s>might</s> will actually work.