Here is a list of free iPhone apps that will make your life much easier.
Mocha VNC Lite – iPhone VNC client, which allows you to remotely connect to a computer running VNC server, and control the screen.
Remote Desktop Lite – iPhone client for Windows Remote Desktop.
Logitech TouchMouse – This app turns your iPhone into wireless trackpad and keyboard.
Google Search – Google search app for iPhone.
Skype – Messaging, voice calling and video calling.
Balance – Keep track of your bank account balance.
Dropbox – Cloud based file storage.
Evernote – Take notes with your iPhone and sync them online.
Facebook – Facebook app for iPhone.
Find my iPhone – With this app you can track your iPhone via GPS, send remote messages and sounds, and wipe the phone remotely.
Microsoft OneNote – Take notes on your iPhone, sync and share them online with other users.
Wikipedia – Wikipedia app for iPhone.