We love this bright idea for wedding receptions: have your guests write messages on cards for you to open on each anniversary. What a great way to look back on your wedding day and look forward to your anniversary each year!
Basically, you just need a bunch of lovely blank note cards and envelopes. Numbering the envelopes for each anniversary year would be a reasonably manageable DIY project. It could even be delegated to someone with nice penmanship or who has patience to sit down for a couple of hours to neatly place pretty stickers like these pink glitter numbers found on the online craft supply store A Cherry on Top: