Read only blockchain in bitcoind , patch ideas This question is related to to the ( already nearing 2 GB and always increasing size ) blockchain download needed to use the bitcoin network, and is referencing this previous question :
Is &quot;Reclaiming Disk Space&quot; already implemented? How effective will it be?
 Please read it before answering  

Currently if I have bitcoind running on 20 machines, or 20 bitcoind running on the same machine, each of them need to download and store 2 GB blockchain, total 40 GB diskspace used and much bandwidth to dowload it 20 time.

I think the easiest way to make it better would be to have a "read-only" blockchain, one of the bitcoind writes it and the others only use it read only to check transactions.

This could be used to be my own trusted blockchain provider, for all my machines and bitcoind running, on the same machine or remotely using sshfs or other mounting options.

Now the questions :
1- How to implement this in bitcoind ? easiest way to do this ?
2- can this be a problem for the bitcoin network itself in any way ?  

Rules : I dont want answers like "try poolserverj" or "you dont need that" please ;)
I already did working prototype for one bitcoind (with one copy of blockchain) managing multiple wallets: https://bitcointalk.org/index.php?topic=71542.msg96212 It is IMHO easiest thing to to with current codebase and it would fulfill the goal to provide for multiple users' wallets independently while using resources for only one running bitcoind.

But the discussion around it died somehow, looks like nobody tried the prototype and I got only some private inquiries.