Use same wallet/address on multiple PCs?

[Hal]

Warning, lots of bad information and wrong answers in this thread!

Addresses are not created in batches of 100 (after initialization), they are created one at a time as they are used, so you always have a pool of 100 unused addresses.

Wallets do hold transactions, all the ones you see in the client window.

You would probably not want to share the same wallet between your home system and your phone, because of the risk of theft, any more than you would empty your bank account and carry all your money around with you as cash. Most people plan to hold a fraction of their assets in their phones.

[theymos]

Would it be possible to modify the client to properlly handle multiple concurrent copies of a wallet? Or the protocol itself needs to be changed for that to work?

Each client would need to know which coins the other clients are going to use. You could do this by having the clients communicate with each other. You could also say that each client will only use some subset of coins. If Bitcoin allowed you to manually select which coins to send in a transaction, you could handle this yourself.

Other changes are needed, as well. For example, I'm pretty sure Bitcoin doesn't automatically detect when another running client sends coins in its wallet until after it is restarted.

[rebuilder]

Personally, I have a "vault" wallet with most of my BTC on it, stored in an encrypted container, backed up locally and in the cloud. I've used that wallet on multiple computers without a hitch. I do make it a point to  only access that wallet briefly, so it's never in use on multiple computers at the same time.

[gohan]

We could, in theory, divide the keys in the wallet, couldn't we? That would make it easier to "take some money with you when you go out". I think there are some proposals in the forum that would allow something like this.