With millions of iPhone applications available the following list are the 10 that everyone should install.

Evernote – Evernote is a note taking application that will sync your notes wirelessly with your computers and devices through the Evernote web service.  It is hands down the best note taking application available for the iPhone today.  Evernote will take notes from multiple different sources including photos, video, audio, text and web clipping.  There are two levels of Evernote’s service, Free and Premium.  The premium service runs $45 per year.  Download from iTunes.

Shazam – Shazam is consistently one of the most popular applications on the App Store.  With Shazam an iPhone can be used to identify and discover new music.  The basic version of Shazam is free to download.  Shazam has recently released a paid version of the application called Shazam Encore that promises to provide faster speed and more more features. Download from iTunes.

Tweetdeck – I tweet from @jgardner04 and use Tweetdeck on both my Mac and my PC.  I have tried other Twitter clients for my phone but have found the familiar interface to be the best.  Tweetdeck is also one of the few mobile Twitter clients that will allow users to manage multiple accounts.  The latest version will also allow you to update both twitter and Facebook at the same time.  Download from the App Store.

Facebook – This app really needs no introduction.  While Tweetdeck will allow users to view and update Facebook feed.   The Facebook app to does most of the heavy lifting for this social network.  The Facebook app allows the management of news feed, messages, and chat right from the iPhone.  The app does a fantastic job of simulating the experience users will find on the web.  Download from the App Store.

JotNot Scanner – JotNot Scanner is an application designed to enhance pictures of documents.  While this may seem like a simple function it can dramatically increase the OCR that Evernote uses.  JotNot Scanner works with a direct link to Evernote.  JotNot can not only be used with an iPhone camera but by emailing scanned documents to JotNot.  Download from the App Store.

Remote – The iTunes remote app is one of the “hidden gem” apps.  Remote will allow the control of iTunes through a WiFi network.  This means that a user can change songs, browse a playlist or search for music all from a familiar iPhone or iPod touch interface.  Not only will the Remote work with iTunes but it will work with Apple TV as well.  Download from the App Store.

Yelp – This application is the iPhone’s gateway to the Yelp city guide.  Yelp provides local reviews of a multitude of different services from restaurants to religious services and real estate.  The Yelp app adds a little something extra for users with the iPhone 3GS.  Yelp delivered the iPhone’s first augmented reality.  This augmented reality uses the iPhone’s camera to allow the user to move the phone around and view reviews in the direction relative to the users location.  Download from the App Store.

Last.fm – Last.fm is an online music service similar to Pandora.  The difference is that Last.fm is more actually described as a cross between Facebook and Pandora.  It is a social network based around the music community.  It is a great way to discover new music and share music with others.  The iPhone application allows users to stream music to their phone and manage their profiles and preferences Download from the App Store.

Dropbox – Dropbox is a file sharing web service that allows the syncing and sharing of files between devices.  The iPhone application will allow for users to access files stored in the cloud on their iPhone.  This ability allows users to keep files in sync when working on the go.  The basic free service comes with 2GB of storage space and the paid service comes with 100Gb of storage space.  Download form the App Store.

1Password – 1Password is a password manager that works with a Mac and the iPhone.  1Password will sync your passwords and other secure personal information over WiFi via encrypted link.  Users can create strong passwords and then ensure that they have them on their phone when they need them.  1Password comes in two packages, free and Pro.  The Pro version provides some additional functionality including copy and paste and Mobile Safari integration. Download from App Store.

What are you favorite apps?  We would love to hear from you.