So, I'm way behind the times here, but I just got a smart phone (yes, it fits in my bindle!), and want to know some of the cools apps (preferably free) that you guys have found to be useful or fun.

Doesn't have to be music-related.

Merci.

I have a whole bunch loaded but the only ones that i really use that regularly are:

Navigation (Google's free GPS navigation app) which I think came pre-loaded
Cor.kz (the mobile version of cellartracker - a wine cellar inventory system with community reviews and pricing info) - not free but cheap and indispensable
Pepperplate (a recipe management database system)
Tripit (for managing travel itineraries)
Opentable (restaurant reservation app)
Reader (Google's rss reader app although they are going to stop supporting it soon)
Facebook
Shazam (song identification)
Soundhound (song identification)
My tracks (hiking)
Alarm & Timer

How do the song IDs work?

You launch the app, hold it up to the song playing, it tells you what it is.

Yep...after about 20-30 seconds of listening, it tells you provided that it knows. I find that one of the two will work about 80% of the time even with relatively obscure stuff.

Google Navigation
ebay
Flashlight
Four Tracks Lite
gmail
gstrings tuner
instagram
MOG (like spotify but you can download albums)
Musical Lite (for finding tempos mostly)
NPR News
Quickoffice
Ultimate Stopwatch (coffee brewing timer)
Soundhound
Yelp

to a lesser degree, Caustic and Plasma Sound for wierd sounds or when I'm bored, i try to write for my imaginary indietronica band NVZBL HRSZ

allmusic
imdb
Flixster
netflix
adobe photoshop express
flashlight
the weather channel
NPR news
The onion
urbanspoon
adult swim
pandora
amazon
google maps
google earth
iTip
Bleacher Report team stream
Espn radio & scorecenter
zappos mobile
wtf w/ mark maron
iQueue
Nat. Geo. National Parks guide
tripadvisor
QR code reader
temple run
flight control

If you tell us what kind of device you have, we would be able to steer you to some better apps to actually be helpful.

+1 on Shazam, Facebook, Netflix, IMDB, Google Maps,

Also:

Spotify (requires premium account)
Audible (audiobooks)
BlueReader (for ebooks compatible with Adobe Digital Editions)
Kindle
Flipboard
AlbumMixer
MoodAgent
iDaft
Sleep101
Fitocracy
AroundMe
Skype

In addition to some of the ones already mentioned (these are Android BTW):

Listen (podcasts)
WinAmp
Chrome
Slate
HuffPost
BuzzFeed
Zite
KEXP
KCRW
Google+ Messenger
Color Note
HBO Go
Phone Silencer
Cam Scanner
Remote For iTunes
Google Voice
Voice Choice
Aldiko (for books)
Groove IP
HP ePrint
Plex
Waze Navigation

AT&T Pantech Flex, so it's an Android phone, I guess? Shows what I (don't) know.