There’s an app for everything. As a traveling business consultant, I rely on my iPhone more than most people. I depend on a core set of apps that help me remain productive during down times: waiting at the airport, waiting for a meeting to start, and “shhhh…” while commuting home. My upgrade to the iPhone 3GS include new features that make working offsite much more pleasant, specifically faster connectivity, faster processor, more storage space, GPS, and a camera that can focus. That last feature, a focusing camera, is by far, the most useful function in my opinion. It allows for easier capture of notes and brainstorming sessions.

Below is a list of 10 (technically more than 10 but I grouped them) apps that I rely on a daily basis.

1. Mail/Calendar/Contacts. The core apps built into the iPhone for mail, calendar, and contacts is a traveling consultant’s dream. The recent 3.0 software update allows for subscribing to CalDav calendars (like Google Calendar), as well as initiate meeting invites in Exchange using ActiveSync. At any given moment, my iPhone provides the same data that I get from my laptop connected to the network. In fact, during this post, I responded to five client emails while at StarBucks.
2. Maps. Another core app that just functions really well. With the addition of the GPS unit in the newer iPhone 3G and 3GS, Google Maps is essential to finding your way around a strange new town. Street view gives you a graphical view of the location before arriving so you can orient yourself before arriving on site. The routing option also gives you the opportunity to route based on driving or walking/transit.
3. Evernote. I originally delete this app because the original iPhone’s camera couldn’t focus and made taking photos of documents impossible. With the new iPhone 3GS, I’m back to using Evernote to capture whiteboards, business cards, and anything I run across. It syncs up information I grab from the iPhone to my other computers, as well as making it available online. Also check out Drop Box for syncing files between your computers and having it accessible via the mobile site.
4. Tweetie/Tweetdeck. Two different apps, one purpose: build relationships and meet new interesting people via Twitter. I use Tweetie for quick tweets, search keywords, and view trending topics. I use Tweetdeck to sync my “groups” between my desktop app and my iPhone app. In other words, I follow hundreds of people, but group them into interest groups to filter out the noise.
5. Facebook. Use this much less for business and more for personal relationships. Monica Guzman (@moniguzman) said it best, ”Facebook is for people you already know, Twitter is for people you will know.” The Facebook app is useful for me to keep in touch with people I already know, mostly on a personal level.
6. Beejive IM. Although one of the more “expensive” apps on the app store ($15.99 original, on sale for $9.99), Beejive consolidates all your IM accounts (AIM, GTalk, MSN, Yahoo, Jabber) into one. The new push notification lets you stay logged in but still receive messages when your phone is on standby.
7. Flip Clock. A much more simplistic app but incredibly useful for meetings. It displays a simple classic flip clock. This is especially useful when I’m doing an interview with a limited time. It lets my interviewee know that I’m conscious of their valuable time.
8. WB Capture. Although the new iPhone 3GS camera captures much better images, I still use this app to filter the scribbles on the whiteboard. The app runs a filter that sharpens and clarifies the writing. Clients love it when I take an image of the board and send it right to them during the meeting.
9. Google Reader. Google doesn’t have very many real apps, instead, their applications are web-based and access via Safari. I created an icon on my home screen to access Reader to keep up with my subscriptions when I’m waiting in line, waiting for a meeting to start, etc.
10. FlightTrack, Yelp, OpenTable. Not really one app, but a few of my favorite apps on my “travel” page. I use FlightTrack to monitor my flight status, Yelp to look up places to eat, and OpenTable to reserve a table once I find a place to eat.