While I would like to have a snazzy little Least Squares Regression Line applet on my blog (who wouldn't?), I have temporarily and figuratively thrown up my hands in frustration over the embedding geogebra wild goose chase. Instead, I have uploaded my GeoGebra file to be viewed on its own html page. I hope you enjoy it. The GSP file that appears elsewhere on my blog has more features, but of course requires the program.
This was a neat sketch to construct because I was able to use the spreadsheet view in GeoGebra, which is pretty slick.
Update: the link now takes you to lsrl9.html, which features, as requested by Pat, a way to view the point (x, y), which is always on the LSRL. Thanks, Pat for the suggestion.