us solicitors general

Just who is the US Solicitor General, and what does he do? And, even more importantly, what was he and five previous US Solicitors General doing at the J. Reuben Clark Law School on Thursday and Friday?

I thought that this quote, from an excellent History of the Solicitor General (found on the pages of the Office of the Solicitor General) was an interesting job description:

The Solicitor General is the only officer of the United States required by statute to be "learned in the law." He is one of only two people (the other being the Vice President) with formal offices in two branches of government. And perhaps more than any other position in government, the Solicitor General has important traditions of deference to all three branches.

So, what does this government officer do, in the position that Thurgood Marshall is quoted (on that history page) as being "the best job I've ever had?"