What can I do with my frizzy, wavy hair?

I have fine, frizzy, wavy/curly hair. When I want to look nice, I have to straighten it, which is annoying and time-consuming.

Is there any product or technique I can use to make my hair look acceptably good by leaving the waves/curls in? I need something that would make the curliness hold up a little better and get rid of the frizz, I think.