Smith was a huge influence on Heinlein - in fact, he essentially invented most of the space opera cliches. They were original when he wrote them. ;)
I retook the test to see if I could come up RAH. Hit it first time.
I've heard of Smith but don't think I've ever read anything he wrote. I don't go THAT far back. :)
Rah! Rah! Robert A. Heinlein...
It was an essay Spider Robinson wrote applauding Heinlein. Robinson suggested Heinlein was a conservative, as I recall (Robinson is not -- a libertarian at best).
In Number of the Beast, Heinlein makes it very clear that there are some writers he was VERY fond of... And there's a hillarious salute to Harlan Ellison at the very end.
Mark