Mommy Does
Ok, granted, you'll have to actually pay to use some of these commercially they are still fantastic and my three favorite sources for stock. Check them out:

10 free HIGH RESOLUTIONS a DAY! Photoexpress.com

A nice medley with sizes ranging from 72 - 300 dpi is morguefile.com

This is the free portion of one of the biggest online stock photo communities: Stock Exchange

Hope you enjoy and find something useful!
Mommy Does
Husband: *Makes awkward squawk sound*

Me: *Looks startled...and seriously concerned*

Husband: What?

Me: Yeah, that's what I was about to ask...*still a bit concerned*

Husband: That was the sound a pterodactyl makes

Me: And you know this how....

Husband: Stephen Hawking told me

Me: *Back to concerned look*

Husband: Seriously, he went back in time to study the sounds that pterodactyls make, then came back, and, in secrecy, told me.

Me: Few flaws in your story, but ok, I'll bite. How, pray tell, did Stephen Hawking convey HOW to make that particular sound?

Husband: Sounded it out...you know "beep, boop, beep" (which, by the way, sounds amazingly like a squawk?)

Me: Why would he tell you? He could tell anyone, why you?

Husband: It's apart of a super secret plan, but he knew that since I wasn't famous I'd pose no risk.

Me: Risk to what?

Husband: *Matter of factly* to the PLAN....geesh

This is a paraphrase, but you get the gist of our conversations. Title sums it all up.