Some folks call the iPad a toy. Ok. I quickly thought of 25 useful things I can do with this toy:
Read & create Emails
Maintain & use Calendar
Maintain & use Contact info
Search web
Use Maps & find directions
Use Weather & travel info
Take notes
Review Documents (docs, spreadsheets, presentations, PDF)
Edit Documents (docs, spreadsheets, presentations)
Annotate PDF
Create simple Documents (docs, spreadsheets, presentations, PDF)
Store & Read trade journals, manuals, & other publications
Track news and markets
Display presentations
Print Documents
Remotely Log in to office desktop
Store and use documents in the cloud
Use project management apps and "to do" apps
Use specific business apps for your industry (real estate, stock trading, design, etc..)
Use as a secondary touch screen for your Mac
Use, create & maintain simple data bases (Bento, Filemaker)
Use business reporting, visualization, and analytics apps (SAP, Roambi, etc.)
Participate in online meetings via WebEx or similar apps
Develop and Draft process flow charts and free form sketches
Perform simple photo editing
Now, I know that a laptop might be able to do some of these things better, but that is really not the point of the iPad. The iPad does these things sufficiently well to meet 90% of the users most frequent needs in a lightweight mobil package that cost half as much as the lowest price MacBook. For this reason, people are buying the product. Add to this that it is fun to use, and you have a winner.