I spent a ton of time trying to get to know entrepreneurs early--even before their ideas are fully formed or before they have their decks. That's where I think I'm going to have the best outcomes and where I'll be able to be the most useful investor--where everyone knows why they're in, what they're there for, and we can all thoughtfully get on the same page about the vision we're trying to move toward. Great! I'm on…
This isn't a strategy that you can use to get access to every investor because like Charlie said, it takes time to build up relationships and really get to know people. However, if you do have a few key people you want to get to know, getting to know they outside of the tech scene can be a great way to build a long term relationship. You need to figure out a non-creepy way of doing so (i.e. don't just start showing up where they check in on foursquare (http://www.feld.com/wp/archives/2011/03/did-someone-ruin-fou...) but at the end of the day, investors are people and they often have causes/activities that they're passionate about and may overlap with your interest.