Prefer a more graphical interface? Check out NextApp's $3 WebSharing File/Media Sync. The program provides you with a URL that, when typed into your PC's browser, brings up a Windows-like visual directory of your smartphone's storage. You can transfer files individually or in bulk, stream music from your smartphone to your computer, and view and play stored photos and videos. There's also a free version that includes only the basic file-transferring functionality.
Remote access Both SoftwareForMe's $10 PhoneMyPC and LogMeIn's $30 LogMeIn Ignition provide full remote access to a PC from your Android smartphone, allowing you to control your computer, run programs, and manipulate files as if you were sitting in front of your monitor.
If you're using Citrix-enabled servers, look for Citrix Systems' free Citrix Receiver application. It lets you sign in to your system from your smartphone and access all of your programs and documents.
Business travel Expensify.com's free Expensify app gives you everything you need to manage expenses while out and about: It offers simple forms for entering expenses, photographing receipts and invoices, and syncing the data to your account at Expensify.com. (Accounts are free for individuals and cost $5 per month per user for companies.)
For even more expense-tracking features, take a peek at ProOnGo's ProOnGo Expense. It can track your mileage using your smartphone's GPS, track time spent with clients, and export all of your data to QuickBooks or to your own custom expense template. ProOnGo charges per user per month, with plans ranging from $27 for 5 users to $290 for 100 users.