If you're waitlisted, don't lose hope. You still have a chance.
That said, don't get your hope up, either. More and more people are applying to a huge number of schools, so schools don't know how many people will actually choose to go. Lots of colleges are putting a large number of applicants on the waiting list, and your chance of getting off the list is slim.
If you're waitlisted at your dream school, you can still try your best to get in. Find out if the list is ranked or not - if it is, find out how you can move to the top of the list. You can call or email the admissions office and tell them about why you should get in (nicely, of course), but I'd say bugging them daily probably wouldn't help push your case.
If the school allows you to send in additional information, do that! Especially if you've accomplished/won something between the time you sent in your application and now. You may or may not be able to send in more recommendations, though - check with the school. If they allow you to, don't send in too many - I doubt they'll all be read.
Keep your grades up! A lot of seniors don't, and this could be what makes you stand out. You may want to send in your third-quarter or final grades as additional info.
Hope this helps, and good luck!