I've found that there are several applications out there that can be a huge help for small businesses that need to economize on office productivity suites or more easily collaborate with partners, vendors, and customers. One of the suites is, of course, Google Apps. These get better all the time, with the off-line Gears functionality a major move in the right direction, but they're still fairly limited in functionality for those of us who are used to Microsoft Office or OpenOffice.org feature levels.
Zoho doesn't get the amount of press that Google gets, but the Zoho suite of applications is quite good, and could easily be the only set of apps you need if (1) your requirements fall into those of the majority of business users and (2) you're pretty much always on line. This week, Zoho announced two improvements to their spreadsheet app, and both are important for business users. First, the Zoho spreadsheet now features pivot tables. If you're doing "what if" work, this is critical. Next, Zoho now understands Visual Basic scripts. For many business users, this is the principle stumbling block in many Office alternatives, and Zoho is right on the mark to take care of this in the spreadsheet first.
If you've been wondering whether there are cross-platform tools that can replace Office, take a look at Zoho. The price is right for SMBs, and the functionality is on a steady path of improvement.