ALBION  Nothing builds with 1.8 under Snow Leopard. Not gimp, not emacs, most of their dependencies fail. Tried uninstalling and reinstalling using instructions given on the web site. Still no luck. A varying handful of important ports are always broken at any given time, but 1.8 achieves new milestones in port breakage.  
(Version 1.8)

BLACKSMITH_TB  If you have 1.7 installed, doing a

sudo port selfupdate

Should update for you (it does for me on 10.5.8, at least).  
(Version 1.8)

VITALENZO  When I try to download the MacPorts 1.8 package for Snow Leopard I get the following error:

Forbidden

You don't have permission to access /MacPorts/MacPorts-1.8.0-10.6-SnowLeopard.dmg on this server.  
(Version 1.8)

JAZZYGUY  The most important application and the most necessary on the Mac. Without this it would be impossible to get the free games, and innovative stuff like "Figlet" and kStars which BTW beats all shareware and freeware astronomy apps available including Stellarium and other apps. It was great that it is now NATIVELY ported to 10.5 and runs great!  
(Version 1.7.0)

ALBION  At long last, the clisp port is fixed! And all of my other 200+ ports are building correctly. Nice.  
(Version 1.7.0)

FONIK  Simply put, if port didn't exist I would not own a Mac.  
(Version 1.6)

GAOSHAN  The package manager formerly known as DarwinPorts is the best thing out there for easy installation, compiling and management of all sorts of unix based stuff.

Super app! Better than Fink, in my opinion, as it seems to have more up to date packages, in general.  
(Version 1.3.2)

ELIASHC  Probably the best package manager there is.  
(Version 1.2.1)