Not only is it important here, it's really important on Flickr.

A lot of my photos show up in google searches, depending on what I put as the title. If I have a good photo that I think has commercial value, I really think about the title now and how it might found via search engine. One of my photos was recently purchased by BFG Communications for an ad, and I'm pretty sure that's how they found it.

Today, the following google searches led people to my flickr site:
1 black and white with a splash of color
2 water balloon popping
3 when food goes bad
4 rainbow spray

Usually have a lot more from "bullet water", "bullet through water", etc.