You'd have to keep your master database on one of your computers, let's say your PC. Then you keep a small database on your laptop of just receipts you're scanning on-the-go. When you go home, you import them into your PC database.
See http://neatreceipts.com/forum/forums/thread/1784.aspx for more info.
(I can already see I'm going to need to write a how-to on this one. We've had three similar posts in as many days about it.)
Hope this helps.
Regards,
Tommy Jordan
3rd & Wayne, IT Services
www.twnetworx.com