Forgive me if I'm off place - but another thread you started stated that you were writing your first script. This is not to presume that you were going to do anything of this sort but it does provide a potential example for others:
Don't go out with your first script. Almost always - it sucks. Mine did. We all want to be that 1 in 10000 that sells their first script, but the numbers speak for themselves; writers do better when they have some sort of collection of quality scripts.
So: write, write and write. Develop a few solid ideas and polish those suckers up. Most agents I know say 2 at minimum, but like everything else there's no hard rule. Worst thing I ever did was go into a meeting with 3 producers with only 1 script completed. When they passed on that but asked what else I had...I had nothing but ideas. People move and forget too fast for that. So having stuff that's ready to show that covers a wider area will help.
So a basic but solid strategy: write at least 2 GREAT scripts and outline another couple ideas. Ensure those are ready, not just written. Starting finding producers that have produced something similar and start inquiring with them. On top of that, look at the agents that repped deals for similar movies and track them down. It's likely you'll have a hard time getting to the big agents - so focus on assistants as well, don't consider that beneath you. Today's assistant is tomorrow's executive. And then...paper the town with submissions (respectfully) - and hope for the best. Don't pester them once they've been sent...they can take ages and as dlevanchuk said - if it's worth, the agent will find you.