Cheerio & Solid Rust Twotter, I switched to Open Office a few months back (from MS Office) and can say I much prefer using it. Thunderbird replaced the Outlook email client.
While on the topic of alternative software I found a much better viewer for pdf files than the Adobe pantsware. It if called foxit - it opens the files almost immediately as opposed to the Adobe crap which takes ages to load.
(I use Opera - its makes IE look the rubbish it is),
Fuji