I never thought to do it with my credit card numbers, but I have a document on my Treo that just has frequent flyer numbers and the like on it.

My wife got audited while in college. She had almost no income, just a part-time job of about 10 hours per week. There were no crazy tax-deductions or anything that a normal person would call a red flag. The IRS did find some mistake reporting and required something like $700 which included a couple of years of…