If you do not have a program you use to track your accounts and cash flow and are looking to get started, a service you might want to look at is Buxfer.

This free service combines all your account information into a single view you can use to track your entire finanicial picture without having to log into each different site. Buxfer automatically categories your purchases so you track what is going where. Additionally, Buxfer offers the ability to track group spending and IOU’s. This is ideal for roommate situations or where you are commonly sharing the cost of different services over time.

Buxfer is Verisign and McAfee secured so this service appears to be safe to use.