Microsoft's new cloud-based Office 365 that was launched on 28 June, 2011 as an alternative to its traditional desktop and server products, has been strongly competing with the purely cloud-based Google Apps for business.
The Office 365 works best in Internet Explorer, while the Google Apps including free Google Docs tools plays nicely in any browser. The Office 365 and SharePoint work best in the Office hub of Windows Phone 7 handsets, while the Google Apps integrates well with Android phones.
Below are ten interesting comparisons between Microsoft Office 365 and Google Apps both on the desktop and on smartphones you cannot miss.
Main Documents List in the Browser

While Office 365 documents are organized and shared for group collaboration and editing by users through SharePoint, Google Apps natively allow sharing and collaboration without a tool like SharePoint
Main Screens on the Mobile Side

The Office hub in Windows Phone 7 opens to OneNote that syncs with SkyDrive, while Google’s official Docs app for Android opens to shortcuts for All Items, Starred Items, Collections and other groupings
Document Lists on Mobile

Word and Excel files with the Office Hub are only shared on a Windows phone through SharePoint, while Google Docs lists documents sorted by the time of the last update
Word Documents in the Browser

A Word document stored on your Team Site in SharePoint will open in the browser for quick editing while Google Docs editor is dependent on a more traditional series of menu items and options. Particularly, a document created in Word or in Google Docs will preserve its layout nicely
Excel and Spreadsheets

The Office 365 that works well in the Office Live Web app for spreadsheets in SkyDrive, doesn’t let you edit spreadsheets in a browser. You only click on an Excel spreadsheet in SharePoint, it will open in Excel. Google Docs handles spreadsheets in the browser rather fine but the full desktop version of Excel boasts more options
PowerPoint and Presentations on the Web

The presentation editing on the two Web-based options is similar
Presentations on the Phone

Presentation tools are relatively limited on mobile phones. A Windows phone opens a PowerPoint presentation only in landscape orientation but Word and Excel files can rotate between landscape and portrait
Calendars

Office 365 offers Web access to both an Outlook calendar and a SharePoint calendar for the Team, while Google provides a system of personal and shared calendars to coordinate interactions among members of the group

Though Email messages look similar when you view them in Outlook for the Web or in Gmail's Web interface, they are sorted by labels in Gmail and live in folders in Outlook
Apps Marketplaces

Both Microsoft and Google extend their online offerings with app marketplaces
Microsoft Office 365 Unveiled by Microsoft
Related links:
Microsoft launches beta of its cloud business suite Office365
Microsoft Office 365 vs. Google Apps: Ten Interesting Comparisons