If I were trying to get a shell on the boxes of as many startups as possible, here's what I'd do:

1. Create a new library, rubygem, infrastructure thingie that was genuinely useful but had a non-trivial setup process.

2. To aid in that setup process, create a script that I recommend be piped into your shell.

3. Somewhere in the middle of that script, silently tar up everything in the users .ssh/ directory and send it somewhere I can see it.