What is the origin of bellydance?

Good question.  And my answer is...I'm not sure.  Many people say different things,
and the truth is - no one is certain.  The most common belief is that bellydancing began
long ago as a dance for women, by women.  The reason for it varies, of course - maybe
as preparation for childbirth, perhaps a fertility ritual, maybe just a celebration of
femininity...but it is generally accepted that it was NOT intended as a showcase for
entertaining men.  Due to some negative associations in the past, bellydancing has
occasionally been thought of more as a "stripper"-type show, and has given the dance
a bad name (if any bellydancer gives you this feeling, please know that it is
not typical
nor is it the way bellydance should be represented).   Any  negative image the dance
has received is definitely changing, and more people are accepting it for the cultural art
form that it is.   Bellydance has branched out into many different forms and fusions,
particularly in the U.S.  But no matter what the form, it remains a great way to
promote self-expression, creativity, and femininity.

The name "bellydance" likely originated from various cultures trying to best describe
the movement style.  It is also known as raqs sharqi, oriental dance, middle-eastern
dance, and various other names.   

Are you supposed to tip dancers at a restaurant or party?

There is no set answer to this question either.  Tipping in general is often a great way
for the audience to show their appreciation of the performer.  The form of tipping
varies.  A dancer may choose whether or not she would like to accept tips on her body
(in the belt of her costume).  Body tipping is generally NOT acceptable in a party
situation, but
may be perfectly fine at a restaurant.  If you are not sure, ask the dancer
or wait staff.  
All restaurants here in SW Florida where I perform encourage tipping in
the costume as a way to engage the audience in the show.   
Please be respectful! The
dancer should direct your attention in some way to the area she prefers tips to be
placed (usually near the hips, not directly in the front or back, also in straps of the top
may be ok).  Some dancers may bring out a basket or other prop to dance with and use
it collect tips.  Or perhaps there will simply be a jar or basket sitting out nearby.  A
festive and culturally-accurate way to tip is to shower the dancer with bills.  In this form,
a basket may be placed in a conspicuous area, or a designated person collects tips
from willing audience members.  Toward the end of the performance, one or two people
throw the bills (yikes, no coins, please!) over the dancer as she dances.  However, if this
method is used, please be sure someone picks up the money for the dancer, as it is not
ladylike for the dancer to bend over and shovel money up off the floor after her show!  
*Note this also holds for tips placed in the costume...sometimes they fall out, because
we're working so hard and having so much fun.  Please understand that the dancer
cannot squat down and pick it up.  Help her out if you can and get it back to her later.

Do I have to have a specific body type to bellydance?  Or can I be too
old/young?

Certainly not!  Curvy, thin, tall, short, old or young - bellydance does not discriminate
against anyone who wants to learn.  Since classes are women-only (although
technically men
can bellydance), it allows you to be less self-conscious about your
body.  And although you need to be aware of any special physical conditions you may
have, as with any form of exercise, anyone can participate.  Keep in mind that for some,
it is harder to learn the type of movements we use.  They are not movements used in
everyday life - so your muscles need to learn how to move your body parts in different
ways.  Don't be discouraged if you can't do a particular movement in one lesson!  And
parents - bellydance can be fun for young girls, and the dance is intended to be
"family-friendly".   But do keep in mind that
sometimes, due to individual maturity levels,
they can be quite giggly when you start talking about moving your chest, pelvis, or hips.  
 Teens will be teens!

What Do You Wear to a Bellydance Class!?!?

Bare feet or ballet slippers (or similar soft, flexible shoe) is preferred; sneakers may limit
your movement.   Some studios do not allow shoes at all.  Wear comfortable workout
clothes, but does help to wear a short or form-fitting top to help see your movements
clearly.  Some people feel like wearing their standard aerobics/yoga attire, while
others prefer getting a little more 'festive' with more gypsy-style tie tops and scarves.  I
do have jingly hip scarves for sale in class - they really do help you feel and see your
movements better, plus...they're fun!  But most importantly - just wear something you
feel comfortable in!
Learn about the local
bellydance community!