Financial management. The easiest variety, I suppose, is to have no money—not much to manage then. Nobody wants to be there.
For real money management, applications like Buxfer can help give you a hand. You can synchronize all your accounts, so you can stay on top of your bank and credit card transactions and balances. That's all good, but what if you're not sitting right in front of your computer?
For times like that, Buxfer allows you to interact with you account via your cell phone. Using a simplified interface optimized for mobile browsers, or even email and SMS text message, you can add transactions to your account or query balances. It can even send you back alerts when you go over budget. Need to make a payment? Buxfer uses Amazon Payments to transfer money online.
Buxfer is a free tool. You do need to sign up, of course, and you'll need to pay your carrier for any text messages you send back and forth to the application.