Maybe you know this application but if you don't, I think you must look at the site
www.xml-sitemaps.com/
I'm using the standalone script to generate and submit automaticaly the sitemap of my new site to Google and Yahoo! You can set a cronjob and the script will works alone It's a great idea if you have a large site, if you always create new content AND/OR if you don't want (like me) loose your time with this job.
I tested the xml sitemap generator with SEF Advance and it works like a charm! I don't know with other SEF Components. I know OpenSEF have a xml sitemap generator but personally I always lost time to "clear" the invalid url's... This problem don't appear with SEF Advance and xml sitemap generator.
This script cost $14 but I love it! It's a good investment in my opinion
Thanks for the link. It is one of those included here:
code.google.com/sm_thirdparty.html
which lists a bunch of free online and downloadable generators.