Facebook and Twitter are good sites to reference for events, but there are a few others of which you should be aware.
If you are an active business, a busy organization, or even just an individual looking for something to do you have many options. Getting the word about about an event is crucial in attempting to attract people to it. You can tweet about it easily on Twitter or make an entry on your Events page on Facebook, but have you heard of LinkedIn or Meetup?
LinkedIn is interesting in that it is a social networking site akin to Facebook though it is geared more towards "professional" networking. You can meet others who are in the business community in some degree and while you are at it find many, many articles from "My Best Career Mistake" so you can learn from the experience of others to Marketing Strategies and the Economy. You won't find Farmville updates cluttering your channel and it will really help give you (and your business if you have one) some great exposure!
Meetup is just that - a site to create events and publicize them to get more attendance! It is very easy to use and to start a Meetup Group. In fact, if you want to see what is going on in the area just follow the link and adjust the inputs. Looking for "Book" within 25 miles of 44870 brought three groups up: Port Clinton Women's Book Club, Port Clinton Mamas, and the Mid-Ohio Awareness Group. Hobbies, Food & Drink, Singles and more (even political Meetups like the Northern Ohio Libertarians) all can be found - or started if you don't see anything you like yourself!
While sites can be useful and powerful, remember that not everyone uses the Internet frequently or is signed up to these particular services. That said, don't be afraid to look at doing things manually and in-person. Here's a quick list of personally-recommended ways to meet others, learn what is going on, and/or tell others of happenings in their area:
*Pay attention to or purchase ad space in local news outlets like the radio or paper making sure to ask questions about the demographics of their audiences
*Look at or post fliers/business cards in the appropriate section of notice boards in public places like the Post Office or private businesses such as drug stores, music shops, or wherever else is appropriate and has dedicated space
*Drop business cards in those little bowls some restaurants have to win a free lunch as others can see your name in the bowl (and you may just win a meal)
*Join a community group of some kind whether it be a faith or service operation; the Chamber of Commerce is another great resource to meet others
Do you have any other ways you get the word out? Or, to which rails do you put your ear so you know what's happening around you?