I'm learning a lot from you. I think it's a good trade off, bigger hard disk space but un-linkable and untraceable transaction. I don't know anything about how blockchain works, but I'm thinking about a wallet which deletes the data which is, for example, a month old and can be used just for send/receive. Another wallet for the network. I haven't read the last posts here, and I guess I will find my answer there.
Wallets themselves don't take up sufficiently large amounts of space, the issue is that the blockchain contains the transactions for EVERY wallet (including mixing transactions in the case of other anonymous coins). As smooth explained, most Bitcoin users are using web wallets (Coinbase, Blockchain.info, GreenAddress, etc.) or SPV-style wallets (Electrum, Multibit, etc.) where you don't store the whole blockchain, only the info relevant to your wallet (which is tiny). All of the backends to those services, though, are running full nodes with the full blockchain by necessity.