The close up adapters are oftern refered to as Rolleinars - or at least the Rollei ones are, which are the most common. In the Rollei series there are 3 of increasing strength. These turn up on ebay regularly - sometimes in sets (through remember you there are TWO lenses to make up each Rolleinar).
Originally Posted by David Ruby
DenisP has one of these, and posted some stuff with it recently: http://www.apug.org/forums/forum51/7897-rolleiflex-rolleinar.html
You might also want to look out for tele and wide angle lenses. These are a bit rarer, but were made by Sun.
Stuff like this is usually listed as either Rollei or Yashica - it should work fine on the Ricoh.