Address Book - Back in the old days, I used to keep a pen-and-paper address book and calendar, which I would need to handcopy my essential contacts and dates every year. Then I went digital with the Palm Pilot PDA, juggling it along with my cellphone and netbook computer. Now, smartphones allow me to keep all my contacts and schedules at my fingertips.
App Store - I'm constantly looking for new tools (hopefully free) that will make my life easier and more fun.
Calculator - Whether I'm figuring out how much tip to leave at a restaurant or balancing my checkbook, this app always comes in handy.
Calendar - Although it's not as great as my previous phone, the Palm Pre, the calendar I have on my current Sprint HTC is still great, combining my Google calendar with my Outlook calendar in one convenient place.
Camcorder and Camera - Although I still have a high-def standalone camcorder and a still camera for those special occasions, I tend to use my smartphone to shoot videos and images to chronicle my every day life.
Clock with Weather - I no longer wear a wristwatch. My primary timepiece now is my phone. It not only keeps an accurate measure of time, but it also provides an excellent forecast of the local weather.
Email - Now, for good or bad, my electronic mail can follow me everywhere I go. While I liked the interface on my old Palm Pre better, my current phone does an adequate job of syncing all of my email addresses in one place.
ESPN ScoreCenter - Anywhere I go, I can now check the up-to-the-minute scores for my favorite sports teams.
Facebook for HTC - I can check my status, post an update, upload pictures or video, read my newsfeed, send messages to my friends, no matter where I go. While my desktop version still offers a couple of benefits, the mobile version is definitely indispensible.
Flashlight - This has helped me out many times when I was scrambling for my keys in the dark or when the lights went out or when I was trying to read a menu in a dark restaurant.
Games - What better way to kill a few free minutes than by playing Angry Birds, 3D Bowling, Dragon Fly, Jewels, Marble Blast, or Teeter?
Google - This is a real must-have. The knowledge of the Internet is accessible any time, anywhere. It's fantastic that we can now have search engines with us at all times and all places.
GPS Navigation - After my stand-alone GPS device was stolen, the GPS app on my cellphone got me out of some jams, directing me where to go.
Kindle - I love my "real" Kindle e-reader, but the free Kindle software for mobile devices is also pretty sweet.
Movie Apps - Whenever I want to look up the showtimes for this week's movies, or check out the reviews, or see what folks are saying about films across cyberspace, I check out Fandango, Flixster, Moviefone, or IMDB.
Pandora - I love this site, and now I can stream some great music directly to my mobile phone.
Quick Office - This allows me to easily view on my phone any Microsoft Word documents, PowerPoint presentations, and Excel spreadsheets.
RSS Feed - All the blog posts I follow, all the news headlines, are all streamed to me as soon as they become available.
Scanners - My phone reads all the Barcodes, Tags, and QR Codes that have become ubiquitous, bringing me the extra info that marketers want to deliver.
Sprint Hotspot - Wi-fi anywhere anytime. 'Nuff said.
Text Messager - Quick, easy, my friends are only a few keystrokes away.
Twitter - I used to hate this little microblogging social network, but it has slowly but surely made me a believer.
Voice Recorder - Such a useful tool! Record a reminder, "tape" something you want to remember later, no pen and paper necessary.
YouTube - Videos! Anytime. Anywhere.
Phones aren't just for talking any more! What's on yours?