I've thought about the email archiving, which I've been doing for a while as it is, problem with that is I'll get emails from some sites that only really say "we have received your order and in the process of shipping it now, thanks" and that's it. Which was why I printed out the receipts

When/if I scan other receipts, it will be in tif format. pdf's are easier to create (select special printer or hit "save as pdf") than a tif file (take screen shot, go to image program, crop out the extra stuff, save as tif). Plus a pdf is going to be smaller. Although I guess with mac's you can do cmnd-shift-4 and just select the area you want to capture and it will save to png (i think there are some hacks to change what screen captures save to, not sure if there's a tif option). I also purposely don't use the meta data because I didn't want to rely on that so I could look at the directory in any OS and see all the information I'd need to know to search for it. Good idea on just moving the receipts to whatever project it's for. I kinda do that already without thinking about it by keep all my work receipts separate from personal ones.