Here's the best system I've been able to come up with. We have three plastic storage boxes, each about the size of a shoe box. One for the current month, one for previous month, and one for the month previous to that. At the end of each day we stack the slips with the daily batch report on top, staple them with a heavy duty stapler, and write the date in large print with a Sharpie and put them in the box for the current month. At the end of the month we toss the contents of the oldest box and start filling it again the next day. This way you'll always have 60 to 90 days of reciepts. Credit card companies require disputes to be filed within 60 days so you're covered if someone disputes a charge. In 13 years I've only had a few times when I had to dig through a box and find one of these reciepts and I've never needed one that was over 60 days old.
I like it! Thanks! These receipts drive me CRAZY and we've never needed one!
The shoebox sized boxes sounds great.