IM:Pidgin is a universal instant-messaging client that works with AIM, Yahoo Messenger, Yahoo Messenger and others.
Graphics: Ubuntu comes with the Gimp Photo Editor, a Photoshop-like application with a surprisingly full set of features. For digital photo handling, there's the F-Spot Photo Manager.
Multimedia: Ubuntu comes with ripping and burning software and media playing software -- pretty much whatever you need. They include Audio CD Extractor, Brasero disc burner, Movie Player, Rhythmbox Music Player and Sound Recorder.
Accessories and games: There's plenty here, including a calculator, text editor, note-taker, screen-capture program and plenty of games, including classics such as chess, blackjack, mah-jongg and Sudoku.
If Linux has an Achilles heel, from the point of view of a Windows user, it's installing new software. Be prepared to enter a new world in which Windows Update is a model of simplicity by comparison, and in which you may feel as if you need a Ph.D. in physics merely to install new applications or updates.
Let's take something as simple as installing the latest version of a Flash Player. I was visiting YouTube, but couldn't view any videos because Ubuntu doesn't install a Flash Player by default. Actually, neither does Windows, so it didn't bother me -- all I had to do was install the player.
I clicked on a Web link as directed, and came to a screen that asked me which version of the Flash Player for Linux I wanted to install: tar.gz for Linux, .rpm for Linux or YUM for Linux. This was, to say the least, confusing: The .rpm version sounded like a car specification, and the YUM version sounded like a bubble gum.
From my experience using Windows archiving software, I've heard of the .tar compression format, so I chose that one. I downloaded it, uncompressed it and ran the installation program. Nothing happened. I tried running it another time. Again, nothing. Then I tried an option that allowed me to run the installation program in a terminal window. It was a shot in the dark, but somehow I had hit the target. Why, I'm not sure, but the installation worked fine.
I experienced similar issues when updating to Version 3.0 of OpenOffice -- and in fact, finally gave up. Version 2.4 worked just fine.
People who believe that Linux will replace Windows as the main operating system on PCs should realize that the mass of consumers don't want to face these kinds of issues when upgrading or installing software.