Google Apps standard Edition (free) offers a suite of communication/productivity/ collaboration tools (and many other 3rd party tools in the Google Apps Marketplace) in the cloud that is great for startups or small business setups-up to 10 users. Easily brandable to your own domain name. Only requirement: a domain name.
Sure, everyone uses Gmail, but if your a small business/startup make it a point to leverage Google Apps. At our startup we had hosted exchange w/blackberry support for 50+ users eventually, cost = almost 10k per/yr. Switched to Google Apps 2 years ago and see a 75% savings (below 3k/yr) and limits are higher as well as features (email, docs, etc). It's no joke.
True, we even have some of those sceptics here in my company, complaing aout powerpoint and excel. I say its the content of the powerpoint that matters, white background and black letters are fine if you know what your talking about :-) I too think these are minor concerns and see it getting better each day/week, and tell ppl to just keep on hanging on.
Generally agree...for anything requiring joint input/collaboration, this is a must. However, for complicated formulas, filters, pivots, etc. Google spreadsheet doesn't come close to Excel. So I continue to use both GOOG and MSFT products.