Ideas for positive ways to mark a sad anniversary?

Monday will be my 30th wedding anniversary.  Regulars here know my story; suffice it to say that my husband deserted me and has irretrievably broken the relationship.  My emotions don't allow me to ignore the anniversary but I'd like to do something positive (and inexpensive), easy or challenging, to mark the day (one I don't feel fondly about) but also to mark my resolve to keep going on my own.  Any thoughts?