graphics
Much easier to use than Microsoft's Office suite, and totally free, Open Office offers great designing, layout, drawing and presentation tools.
An alternative to Microsoft Word, this open-source word processor is easy peasy to download and install.
Draw and paint and create something funky for your organisation...or just have a play yourself (the programme dowloads in a thrice, as it is not very big). Free and great fun!
I'd be lying if I said that this open source alternative to Adobe Photoshop was easy to use, but it does have roughly the same functionality plus a few extras.
I've only just discovered this, but I'm totally captivated by both the name and the character of the package!