I use Quicken for tracking my finances. Luckily my bank has everything linked up electronically, but the one thing my bank can't do for me is to tell me where the cash has gone, once I get it from the machine.

But, lately I have been using my RTM to keep track of cash that I spend, so it can get entered into Quicken sometime later, when I have the program open. I simply enter one new item on the "Cash" list, with today as the due date. Then, when I finally enter them in Quicken, I mark them completed.

These entries can be short and sweet like "Cafe 15 ^today". Or they could be longer, such as when I charge lunch on my card and then collect cash from friends (also known as "ATM by proxy"), -- these might look like "Brunos Visa 45.38 Dave 15 Devin 15 ^today". Sometimes I also enter a quick balance entry, like "On hand 43 ^today" to tell myself how much I had at a certain time.

Using this, I have gotten better at accounting for my cash spending, though there's usually a small amount of Untracked left over anyway.