To make that more survivable it might be handy to have a way of generating a keypair from a memorable password or phrase. So you could have at least one and maybe a few private keys in your head easily, needing only access to the app that can turn that into a private key fmatching one of your addresses you keep a stash in. I am not familiar enough with how much latitude one has in inventing keys to know if that is at all feasible though.
If not I guess one could come up with schemes for inventing mnemonics for private keys then generate lots of keys with corresponding mnemonics until you find one you find memorable.
-MarkM-
If the client supported generating a keypair using a strong password as a deterministic random number seed (such as by hashing it and generating the keypair from the hash, instead of from random numbers), then you could always generate that same keypair from scratch as long as you knew the password.
This could also help websites systematically generate addresses without needing constant access to a wallet or a bitcoind instance...e.g. sha256("i-am-generating-an-address-for-invoice-number-65432-salt-salt-salt-salt")
