Yeah, except the lightning strike occurs for a few millionths of a second and we don't really know where exactly it is going to strike... so it'd be a tad hard! Hence Swansont's "just not practical".
- Perhaps a satellite to focus on an area of positive/negative Ions, condensed. Maybe with this we could "estimate" Lightning strikes however, being able to filter all the Amps and vaults and being able to "catch" the strike would be almost impossible. Luck and filters. That is the closest you would get. . .
Just my thoughts, soon, maybe someone will prove us wrong.