found a desk chair  

Nice find
Looks like it would be a pretty standard office chair in terms of comfort.
Certainly worth more than $20 in good shape with leather.

I have the exact same chair
Leather, soft, and it's very comfortable. And $20 is a deal, I bought mine for $65.
And the current list price at Knoll is $2000-$3000, (though I don't know who would be crazy enough to buy them new at this price, when they are so readily available used everywhere at $150-$200).
http://www.knoll.com/products/product.jsp?prod_id=410&flag=cat&cat_id=23

They are indeed very...
They are indeed very comfortable. For the record, these chairs sell for around £300-500 second hand in the UK so $20 is a steal.

Nice score
I'm sitting in a cloth one I picked up for $5 at a local resale shop and can attest that it is, indeed, a comfortable chair. It doesn't have the bling of a HM Eames aluminum group chair, but it's really nice, and at $20, you made out like a bandit!
fm

I bet the leather is really...
I bet the leather is really nice. I don't love the plastic back .... wish it was wood. But, yes, a great deal. I am sure the face that it will function so much better than what I have will make me love it!!!!!

comfy
I'm happy with it. It's rather comfy. After some elbow grease with some Mother's Polish the metal looks great. There are just a couple of scratches on the back (I am assuming there is no way to conceal them?). All in all it cleaned up really nice.
The leather is dry and has some scratches. What would you suggest to renew the leather some? Some kind of conditioner?
I'll post a photo when it's all clean.

Saddle stuff
I live in a very "horsey" town and the debate is endless in the equestrian community about the best conditioner for saddles and tack. If you google saddle soap and saddle conditioner you will find forum after forum that tells about the different brands of saddle soap and saddle conditioner. Let me tell you, these horse people are obsessed with their leather issues because they actually have to wash their saddles and tack after they use them to get the sweat and grime off and then condition them, every single time they ride.

I have to say that after...
I have to say that after some days I am so happy with my purchase. Function is a truly great thing. I should have had a comfy desk chair long ago. It's a real lesson in function vs. aesthetics for me. While there are a few better looking options in my mind, this chair is rather nice after being cleaned up and the wonderful function of comfort makes me love it even more, even aesthetically. Perhaps because I associate it's aesthetics with satisfaction? The leather doesn't hurt either, as I am a big fan of it ... it ages gracefully. And Knoll has high quality leather at that.
If something isn't working for you, even if it is beautiful, I urge you to rid yourself of it.

'If something isn't working for you, even if it is beautiful, I urge you to rid yourself of it'...
... DAF gone...