Unless you have an already active company that has interesting just-in-time news or announcements that your clients want to hear.. like (hamburgers 20% off today) don't bother.. twitter is seen as a just-in-time news thing... Build it after you already have audience - Think of it as communicating to already active audience... not build a audience... Not worth the time.. or the effort..
Just my two cents
Steph

Get a bunch of your craziest wackiest friends over one night.. Get into your favorite bottle of spirits.. Bring out a white-board and ask a single questions to be answered by the end of the night:

What can we do with our product/service that will be so entertaining and memorable that at the very sight of it, people can't help but to talk about it... (Think - Jean Claude Van Dam - Volvo stunt) Or (West jets christmas giving video) there are endless examples of demonstrations of product services that the media would love.. Believe it or not, when you are having the most fun, are the most carefree is when you are most creative... (Hence the spirits- teeheee) Anyhow, when you finish the brainstorm.. which should be probably after a bottle or two.. you'll have everything you need to have a story.. You just have to trust you gut and pick the most amazing, fun, enjoyable, example of your best product/service demo, and you better believe if you can't wait to show people... They can't wait to show it to others.. that's how you become.. Newsworthy....
Just my two-cents...
Steph

What I've suggested in the past that worked really well, is to pick an open minded business to advertise for... use your advertising genius to send them customers, as long as the customers when they go into the business say - (X Sent me) - then when you know you've sent them a good deal of customers.. call them up and say did you notice all the customers that said X sent me... Well we do this to prove that what we do works... In order for us to continue this campaign it will cost you (X) the price should be 1/3 of the potential profit that those customers would bring to the establishment within a 6month period of time.. So now you've proven you service works.. All you have to do is turn off the taps if they say no. Rinse and repeat until you find someone that says yes.. which we find that we usually get about 85 to 90% conversion on a strategy like this... No convincing, no haggling, no price negotiation - Here is what it does with proof.. Here is what it costs... 1/3 of the profit. Let's do it.. Yes or no? :) Hope that helps!

We've had some great success with eventbrite.com. I could give you better suggestions if you created a list of your requirements. However, eventbrite has really outdone themselves and probably has covered most everything you'd need.