John Salzi's Old Man's War earned all of it's online praise, it would seem. I started reading it Sunday morning, and was finished by Sunday afternoon - your classic page-turner. The back-cover blurbs already cover the obligatory comparisons with Starship Troopers and the Forever War, so's I don't have to; more importantly, Old Man's War is an example of the social-didactic space-infantry genre which doesn't collapse under its own ennui and existential dispair. It is, in fact, funny in fits and starts, although it isn't a comic novel by design.
The basic plot of the story is that Americans (and presumably, other First-Worlders, although it isn't stated outright) can't emigrate to the outworld colonies without first doing a hitch in the Colonial Defense Forces, the CDF. Furthermore, the CDF has some sort of monopoly on life-extension technologies, which they will only extend to their recruits, who can join up starting on their seventy-fifth birthday. The back cover promises "Starship Troopers without the lectures", but in a fit of irony, I only noticed this after reading a lecture by an ex-politician private in favor of diplomacy over simply killing everything that moves. Oh, well, it's no great spoiler to report that he's quickly put down before we're exposed to more comically inept lecturing. I entertained myself by trying to guess which ex-Secretary of State he was supposed to be - my guess was Cyril Vance.
The novel is quick to the point of glibness, and too sharp to get a good grip on; in short, it goes by a little too fast. It's the author's first book, and he might have wanted to take a little more time getting where he was going, in my opinion. But it's still a pretty damned fine book on its own merits. This little experiment in taking blog recommendations on novels such as Weapons of Choice and Old Man's War seems to be a success; I will probably go on to look into the books from that Atrocity Archives fellow that Reynolds and Bainbridge have been going on about.