Been eating Activia or Yoplait lately? See their pink lids? My husband and I have been saving up our lids, dragging them home from work (after a good lick, of course), and keeping them in a ziploc bag to enter online (the Activia ones) all at once and send the Yoplait ones in as well.
As I write this - actually, I took a little break to write this - I am putting all my codes in at the Activia site, all at once. It is a great task when you're at home from work with your husband who threw out his back. Isn't that awful? Well, maybe that's why I have the time to do it on a normal busy day, really.
I think that's the trick with things that add up. Keep them and then do it all at once. Works with laundry too, you ask? Well, maybe not so well as it takes much longer, but for other things it can:
*dishes from the day (note I mentioned day, not week)
*sending short email responses
*you name it
What do you save up and do all at once?
For more ideas of what works for others, see We're That Family.