If there were some simple rules on how to pitch successfully to investors, as a startup entrepreneur the first and foremost choice would be to attend events and create a presence in the market.
Burt Hammer, founder and CEO of Hydrovolts who is creating a lot of buzz had attended numerous events and won plenty of awards. It would be ideal if every new entrepreneur can attend as much as events possible to promote their startups.
We tried to gather as much as details regarding startup events and meet ups, hope this helps.  If there are more please feel free to add them.
Europe Start Up events
http://fowa.com
http://thenextweb.com/conference/
http://devnest.org/
http://www.thishappened.org/
http://2010.dconstruct.org
http://lanyrd.com/topics/hack-day/
http://paris.startupweekend.org/
http://startupdigest.com/2011/05/03/paris-startup-events/
http://www.leweb.net/
Paris
http://www.leweb.net/
http://startupdigest.com/2011/05/03/paris-startup-events/
US – Washington

http://bit.ly/dcmeetups
San Fransico
http://www.meetup.com/106miles
http://lunch20.com
http://www.vlab.org
http://www.meetup.com/svnewtech/
Hacker News’s “Work at a startup” event (by invitation)
TechCrunch after parties
The Launch Silicon Valley conference
http://sfnightowls.com/
http://startupdigest.com/
http://eventbrite
http://www.skillshare.com/learn#&ca=5
http://www.businessinsider.com/startup2011
http://launchsiliconvalley.org/
http://thefounderconference.com/

New York
Arts, Culture and Technology
Food + Tech Meetup: http://www.meetup.com/food-tech/
Hack & Tell Meetup: http://www.meetup.com/hack-and-t…
Hacks/Hackers Meetup: http://meetupnyc.hackshackers.com/
NYC Lean Startup Meetup: http://www.meetup.com/lean-startup/
NY Tech Meetup: http://www.meetup.com/ny-tech/
http://www.feastongood.com/
http://www.meetup.com/BLKNY30/
https://founderscard.com/