LOL!!!

If your smart enough to know those names, you should be smart enough
to know he need to see the Vet!

You should take your own advice, Rona Yuthasastrakosol.

Although deliberately false, and maliciously given, your response was no
more worthless than any of the well intentioned responses to my original
post.  I normally wouldn't bother responding to such a trollish post,
but I wanted to correct the disinformation you've published worldwide.

And speaking of parasites, the correct answers are:

Yes, it's a tapeworm, or specifically, the gravid proglottids from a
Dipylidium Caninum tapeworm.  I found the answer here, within about half
an hour after my original post:
http://www.fabcats.org/
http://www.vet.cornell.edu/consultant/Consult.asp?Fun=Home

Neither web reference is very non-vet friendly, so it was difficult to
determine the seriousness of the condition, and the risk of contagion,
but I inferred that both were low.

After about a day, the responses to my original post were:  "Take it to
the vet." "Take it to the vet asap."  "Take it to the vet immediately,
you lousy cat hating animal abusing troll."  And:  "It's a tapeworm."
(Maybe I read a little too much into some of the responses).

On another thread, the one about the kitten's "changing lower lip", I
found a link to yet another veterenary diagonistic site:
http://www.marvistavet.com/
Which led me to this page all about common tapeworms:
http://www.marvistavet.com/html/tapeworm.html

This page has a diagram showing exactly what I saw around my cat's butt,
and explicitly described in a followup post.  Both my post and the web
page mention that the best time to witness worms crawling out of the
cat's (or dog's) a.shole is while it's taking a nap.  The web page also
informed me that the condition is not life threatening, or even health
threatening for the cat.  Nor is it directly contagious, since the only
way to get a tapeworm is if you eat a flea containg a tapeworm larva.  I
still checked my own a.shole pretty thoroughly, though.

I had a whole weekend to research tapeworms, and on Monday I learned
that the tapeworm medicine is readily available over the counter, so I
didn't even need to take the cat to a vet.  Since there was no urgency
to treat the condition, I gave the cats a flea treatment to reduce the
likelihood of re-infection.  I waited a few days, then administered the
tapeworm pills.  As of Friday, no more proglottids.

Finally, the "marvistavet" web page recommends treating only the pets
with obvious infestation, and then re-treating only when infestation has
obviously returned.

As Rona Yuthasastrakosol figured out, my original post was, for
practical purposes, trolling.  I never expected any worthwhile
responses.  I didn't get any worthwhile responses.  But I did post
followup reports with more information as I learned it, accurate to the
best of my knowledge.

There are a very few people regularly posting to this newsgroup who:

A.  Answer the question.
B.  Supplement the answer with personal experience and,
C.  Substantiate the answer with references.

Answers and advice are worthless without B and/or C.  The generic answer
"Take the cat to the vet" is universally worthless.

I've learned a lot about cat health and behavior from this newsgroup.
There's a lot of garbage to sort through, idiots who post deliberatly
misleading information, for example, but computers are good at sorting
garbage and filtering idiots.  I try to post useful information and have
fun while I'm doing it.  I hope that cat-owners around the world are
even now lifting their napping cats' tails and checking them for worms
because of what I've posted here and previously.  And if they find
worms, they need not panic and rush the animal to an emergency clinic.