where do you go for replacement glass?  

Any local glass company
can do what you want.

not better / easier to just...
not better / easier to just order online?

No
.

Agree, you'd want to pick it ...
Agree, you'd want to pick it up and check the edges and surface yourself, put blankets in the back of the car beforehand if you're doing it that way. I'm a late and happy convert to internet shopping but there are some things that never should be bought that way.

do not be lazy
judson,
Asking about replacement glass is one thing, being too lazy to look in the Yellow Pages or do a "google search" for a source is another. I am sure that you are able to look up glass dealers in you area. Do you own homework. And of oourse you would get the color, cut, and bevel to match. Your question is pathetic.

well i'm not sure if the...
well i'm not sure if the question is pathetic?and I appreciate all the advice I have gotten in this forum. i'm not a professional interior designer and on a somewhat strict budget here (for both time and money). I work 6 days a week 10+ hours a day?and will be until the new year. I looked up local companies and they all have terrible websites. I found a "local" company (dulles glass and mirrors) that is out of my area but has a decent website with what i'm looking for in stock. If I don't like it, i'm out $100. For now, it's the best move I can make because I just flat out do not have time.
Now, if a REALLY nice piece of glass is worth looking into I will do so in the new year!

excuses are meaningless
judson,
Everyone is busy. I do not even know what my vendors web site looks like. I use something called a telephone and "face to face" contact. I also contacted Knoll and got the "exact" glass specifications and had the replacement glass cut to these dimensions. Not bigger or smaller nor thicker or thinner, exact. Upon considering the source, you question is not pathetic. it is you who are an underachiever and continue to be lazy. You have no reasons for your lack of progress, only meaningless excuses. If you loose $100.00 it will be your fault due to your lack of resolve. Buy some willingness with you money.

touche!
I am aware that...
touche!
I am aware that "everyone is busy". I wanted to get a piece of glass that would enable me to use this table. Currently, I don't have any furniture in my apartment. So waiting for a custom order of glass is not ideal right now. However, I would love to have the exact specs from knoll. Any chance you want to share those here. I have looked EVERYWHERE and cannot find the same edge detail.
thanks again

Sure - I will help
judson,
Contact the nearest Knoll Showroom. If you are in the US and do not meet with success, Knoll Chicago is my vendor and go to source.
They supplied me with the specifications for my MR table and I had a local glass dealer cut the diameter with a "CNC cutter" and bevel the edges to the original angle. This is not a "special order". Most commercial glass dealers should have the glass in stock and the only tasks are the cutting and beveling. It is a one day order under normal circumstances. Call in the order, email the Knoll specifications, pay and pickup the product. Even with limited time this is about as easy as it is going to get. Good luck.
*The CNC cutter will yield the tightest tolerances.