Congratulations on 300 found!  It is a big deal to me (55 found).  I thought you might want to check out this web page http://www.geomilestones.com 

They sell pretty cool stickers that say "50/100/200/300/400 found" on them.  I have a "50 found" sticker that I proudly wear on my Xterra!  Ok, not as proudly as I would a 300 found, but I'm working on it.