Heinlein's heir

I just finished a book from last year (I waited for the paperback) -- John Scalzi's "Old Man's War" -- that I highly recommend to science fiction fans. Its the first thing I've read in a long time that reminds me of Robert Heinlein. It starts this way -- "I did two things on my seventy-fifth birthday. I visited my wife's grave, Then I joined the army." -- and just gets better and better. The protagonist is John Perry, who joins the Colonial Defense Forces because he has nothing left to keep him on Earth. He is "installed" in a better-than-new young body; in return, he agrees to  fight aliens for up to 10 years in a crowded universe with few habitable planets. As one reviewer said, "Its 'Starship Troopers' without the lectures. It's 'The Forever War' with better sex." Great read.