When I think of the most important apps I have installed on my Android phone, outside of the basic call and SMS functions. The Gmail app quickly comes to mind. I can not only send and receive email on it, I can search the through the several thousand emails stored on Google's serves. And syncs my contacts and calendar to my Gmail account too.
HTC's FriendStream is another. It can keep you Twitter, LinkedIn, Facebook and Plurk updates all in one place.
Than there is Dropbox. Victoria Barret of Forbes wrote an article about Dropbox. I am writing this post, mainly to thank Dropbox for the service they have given me. I am one of their non-paying clients with now 4GB of free storage available to me. This is one way of saying thanks.
I have Dropbox installed on a Linux laptop, a Mac OSX laptop and a Windows laptop. I have it on my Android phone too. Instead of keeping my files in My Documents, I keep them in the Dropbox folder. What does it do. Through an Internet connection it will sync the files in the in the Dropbox folder so that in every computer I have, all my files are the same.
Lets say I create a word document in my Linux laptop. When I save it, the file will be saved on my hard disk and on Dropbox's server. Later when I open my Mac OSX laptop, the Dropbox app will connect to the Net and compare the contents of Dropbox folder on my Mac to the contents of my Dropbox account online. Detecting a new file it will download it on my Mac. When I modify the document, it will later update my Linux or Windwos machines, when I turn those on. Basically, it keeps a copy of your files on the hard drive and on the Dropbox server.
From my Android phone I can access my Dropbox account, and download from and upload files to it. If I did not have any of my devices, I could access my files on Dropbox through any web browser.
Dropbox gives you 2.25GB of online storage free, and you can earn up to 8GB more by completing tasks or making referrals. You can also buy more online storage.
Apparently, Dropbox was at least part of the inspiration for Apple's iCloud. Even if you are an iOS user, I would recommend you use Dropbox instead. This gives you the option to use different devices. Dropbox works on Linux, Mac, Windows, iOS, Android and BlackBerry. iCloud only supports Apple devices and has very limited functionality on Windows. So unless you are sure you are never leaving the Apple ecosystem or mix Apple and non-Apple devices, Dropbox is a more portable choice.
Anyway, here is a link to the Dropbox website. Give it a look.