There is no doubt that the microblogging site Twitter is one of the hottest sites out there right now. Even the non-internet or less than average internet user has probably heard of Twitter by now.
One of the things that makes Twitter so popular is its simplicity. Just about anyone can figure out how to create a Twitter account, login and make a Tweet (post).
There really isn't much to Twitter aside from the additional cell phone (SMS) integration capabilities (not required to use Twitter).
The only drawback is because of the cell phone (SMS) integration anything you Tweet (post) is limited to 140 characters or less. Sometimes this is difficult to really say or post much with such limitations. But this is part of what makes it so popular. People actually tend to read Tweets because they are short and to the point. People are less likely to read something that is lengthy, spans an entire page or more.
If you haven't tried Twitter out you really should take a few minutes sometime and check it out. It is one site that you can figure out FAST! It's totally FREE to join. Some people use it to just communicate with friends and family, while others use it to promote a web site, event, show, etc.
You might even Tweet (post) a few updates and links related to your Dolphin site. You might be surprised how many people will take a look.
If you are already familiar and like Twitter, you might be interested in these other popular microblogging sites:
Tumblr very similar to Twitter. Instead of Tweets you Tumble (posts). One of the nice things that Tumblr has that Twitter don't is besides text you can also add photos, videos, etc. in your Tumble's (posts). This is a nice feature, and can really help you if your goal is to promote.
Plurk is a lot like Twitter too. It has a few more options in your account settings then Twitter has, but overall it's relatively similar.