Many businesses use Microsoft SharePoint to enable collaboration over Office files. Dean Beeler's $15 SharePlus Office Mobile Client lets iPads be part of that collaboration. You can test it out with the free SharePlus Lite version.
For just file exchange with SharePoint, Aircreek offers the $7 Filamente app. And consider getting the free Moprise if all you need to do is view SharePoint-provisioned documents, and cut and paste their text into your other iPad applications.
ERP and CRM access
The free SAP BusinessOne lets you view reports and content, process approval requests, and manage client and partner data in your SAP ERP system.
TE's $1 SAPplApp provides access to your SAP ERP system after you connect to your corporate VPN, so you can monitor your business transaction data.
Resco's $50 Mobile CRM Enterprise gives iPad users direct access to a Microsoft Dynamics CRM server, so they can manage and monitor customer relationship and sales transactions on the go.
Mobile Edge for Microsoft Dynamics, Mobile Edge for Netsuite, Mobile Edge for Oracle Siebel CRM, and Mobile Edge for SugarCRM are all client apps that let you connect to popular CRM and ERP systems. The iPad apps are free, but service pricing varies based on number of server licenses.
RhoLogic also lets you access SugarCRM systems from your iPad. It's free, but a subscription license required for its server software.
The free SAP BusinessObjects Explorer lets you connect to SAP's business intelligence tool to explore sales trends and the like, then share the results with colleagues.
With the free MicroStrategy Mobile for iPad, you can access performance and other metric dashboards set up in a MicroStrategy business intelligence server.
Analyze your Excel, Google Docs, or Salesforce.com data visually with Mellmo's free Roambi Visualizer. Licenses start at $99 per user per year.
If you run a website and monitor its traffic with Google Analytics, Inblosam's $7 Analytics HD lets you track that traffic and run reports from your iPad.
Business travelers whose companies use the Concur travel service (aka Atlas Travel) to manage their trips can track their itineraries and always have the details available through the free Concur Mobile app.
Turn your iPad into a travel alarm with iHandySoft's $2 Alarm Clock HD Pro, so you don't oversleep on the road. It detects your current time zone and shows the current weather.
Get weather reports wherever you are over your iPad. Shifty Jelly's $2 Pocket Weather World HD app includes more than 60,000 locations worldwide. The Weather Channel's $4 Weather Channel Max provides weather conditions and forecasts across the globe, bookmarks unlimited locations to track, plots local landmarks such as schools and golf courses on its map, and provides access to traffic cameras in some areas.