You know, I've never even tried that; but yeah, I just called my land-line, and was able to leave a message on my answering machine while clicking links and opening new web pages on the browser. That's using wifi for the browser; let's see if t-mobile will let me both browse the web and handle a call at the same time... yup, that works too. (I'm in the US, though, don't know if cell service elsewhere would work the same.)

Funny thing, the guy (or answering machine) on the other end of the line gets to hear all the "click" and "swish" sounds made when you're hitting icons and navigating links.

Edit: Drat, someone else answered this one before me.