Okay I caved in and bought a Colorado 300 from everyones favorite online mega auction site.
The Colorado did not work on the first wherigo cache which I tried. (geobot near Seaside/Monterey city limits)
I then tried a second wherigo and that one worked. (Memories near Lovers Point in Pacific Grove)
Then decided to turn loose of some additional cash and purchased a Nuvi 550 which has the wherigo functionality. It worked on the wherigo cache which i tried unsuccessfully with the Colorado.
Since then I have downloaded and applied updates to the Colorado - as suggested by our local wheri-guru. I have not yet tested the updated Colorado on that first wherigo.
At this time I am prepared to accompany anyone who wishes to try "geobot" or "Memories". Best time for me is after work on weekdays. Could probably make it for a 5:30 start time.
I am planning to try another wherigo this afternoon. If that goes well then I will add a third wherigo to the list. If anyone wishes to tag along today then I need to know before 1630 - which I realize is extremely short notice.
Anyway if you want to get the wherigo icon and/or see what wherigo looks like on the Colorado 300 or Nuvi 550 then reply to this post.