23-24" from end to end, for me. I usually use 5.5-6' long darts, with the atlatl. I never use weights, either. Aesthetically, they never impressed me and I never believed in them. When somebody can show me some good solid science proving they actually improve cast or accuracy, great. I still probably won't use them, but I will be impressed. Once I picked up the sling though, I sort of set the atlatl off to the side. I've since started to pick it back up, but I'm not nearly as familiar with it, yet.

I have not yet made an atlatl, but I have read a lot about them (including Atlatl Bob, and now Tom Mills on making cane darts -- Thanks, SEB!).  My understanding is that the weight on the thrower is used to alter how it flexes.  The thrower and the spear both flex; what you want is for them to bend as you begin your motion, and straighten as you finish.  That way, the energy stored in the flexing wood, is returned to the spear head as increased speed.

Tuning your atlatl to your spears, can be done two ways: shave the atlatl down, or add a weight; both will make the atlatl springier.  But shaving the atlatl is a one-way thing, you cannot add wood back.  The weight can be increased or decreased, giving you a springier or stiffer atlatl as needed for different spears.

On the other hand, it seems fairly easy to tune new spears to match your atlatl.  So whether to use a weight or not seems more a matter of preference.

Thanks for the tip about Bob Berg.  I have read his

article on atlatl weights

, and I believe he said essentially the same as I did, concerning the purpose of the weight: but he said it better, with more detail, and with a lot more authority (because he uses atlatls whereas I have just read about them).

Berg does have one important point that I missed: the weight makes your throw a bit slower, and thereby perhaps a bit more controlled.

Ya... I'd defenantely try to make one first before buying one of those expensive ones!
Of course im stuck in the desert where all we have is some tall bushes...some people call them trees....ME? YA RIGHT! So it will be hard to find a good piece of wood to make one out of...
yes feel sorry for me and wish me luck...

i can get arrested too, i just make sure noone catches me.  i sneak onto private land and pretend not to see the signs that say stay away.  (it's not like anyone would really care anyways, it is pretty much a huge pile of woods behind all the local houses that noone ever goes into anyways.

sometimes if there is a nice tree in plain sight i sneak out in the middle of the night dressed all in black with a t-shirt ninja mask (google for instructions.  can look pretty good) and a saw and take it down.

but i don't suggest you do this because it can cause lots of problems if you get caught, or if someone sees you they will think you are a burglur or something of the sort