I have recently been searching for a good job board too. I have found 3 different free options and implemented all of them. However, I settled on the last one because of the advanced functionality. Try Jobamatic by Simply Hired.
You can integrate the jobamatic board right into your site. Other solutions did not have this option just widgets and linked boards.
Check out the following post on integrating the board into your site with a page template. Works great if you edit the template file just a little to include your theme header and options. Look at your theme's index.php and go from there. I am NOT good with php and I figured it out. All except for how to remove the default header section from jobamatic's file. Maybe I could just upload a single gif logo? Any thoughts or help for me on this subject would be greatly appreciated?
If any of you figure out how to get rid of the default page header (it is not needed on an embeded page) please let me know how you did it. If you would like to see how I did the board on my website check out MPK Media.
One more thing if you want to see the other solutions you can find them here: donanza.com or jobthread.com. I chose the jobamatic board because sites like LinkedIn, MySpace, BusinessWeek, CNNMoney.com and The Washington Post use it for their job listings. Their database has around 5 million job listings. It also has an advanced XML option to do exactly what you want to do. Good luck and let me know how it works out for you.