I'm a Russian guy, living in Siberia. I have a great team and a prototype of a kick-ass project. I'm going to LeWeb 2010 (Paris), which is the biggest European web conference. There are going to be a lot of VCs. How do I get them to see my prototype and invest in me, if I don't know anybody there? We are looking forward to moving to the Valley as soon as we get funded, so Siberia is not the case. Also, I'm not giving a speech at the conference.
Sorry for the self promotion - but you should consider applying to present at Startup Riot - an annual conference I do in Atlanta. We're heading into the 4th year with a projected 500+ attendees. We have a lot of investors show up and we actively screen out service providers (lawyers, accountants, recruiters, consultants, etc.) so it's a valuable and networking rich environment.
Events like this are a better way to get attention since presenters at Startup Riot get 3 minutes to tell their story in front of the entire audience.
Anyways, take a look - startupriot.com. There are other great conferences too that let entrepreneurs pitch too. Just don't go to any that charge presenting entrepreneurs money to present (pay to pitch). That's just wrong and evil.
Feel free to ping me on Twitter if you have questions.
You may have to get permission from the conference for little Tweetup, but organize that effectively, and make sure to invite any VCs (if they're on twitter). You'll need a meeting space. Broadcast on something such as justin.tv, make sure you have a hashtag and you've reached out to a strong audience of followers far prior to the conference. It will be your own little self-directed broadcast. Exciting!
As with any marketing campaign, you have to "get them where they are".
If you know the names of some VCs (some of whom may be in attendance), another suggestion I'd definitely make would be to find out what discussions they participate in online, and hit them from there. You can usually find them by doing some analysis of backlinks to their websites (if they have a strong online presence). - this basically just elaborated on Tim's comment.
The best way to get their attention would be to show them one graph, which shows that you have incredible customer signup metrics, and you just need cash to put into marketing and fertilizing a 'money machine' that is already proven. The two numbers to go with this would be your 'customer lifetime value' and 'cost to acquire a customer'. If you don't have this graph, and don't know those two numbers, you may not be ready for VCs. You may want to consider other sources if you only have a prototype.
Based on my personal experience, all you have time for is an elevator pitch (practice it). If the VC is interested, you may get a slightly longer conversation. Your main goal is to gather a bunch of business cards and get to know people. You'll really only get your meetings with them either (i) by arranging a meeting now with them at LeWeb (many people fill their schedules with pre-booked meetings at conferences), or (ii) arranging a visit to the city where they live weeks after LeWeb to make a direct pitch.
You're probably also at the stage where the very best thing is to get to know the VC. Use the first conversation with them for a chance to pick their brains and get feedback on your product. Use their experience to your benefit. Good luck!!