What are some compelling reasons to use Electrum?
Why Electrum?


Instant on: Your client does not download the blockchain, it uses a remote server.
Forgiving: Your wallet can be recovered from a secret seed.
Safe: Private keys are never sent to the server. Information sent by the server is verified using SPV
No downtimes: Several public servers are available, you can switch instantly.
Ubiquitous: You can use the same wallet on different computers, it will auto-synchronize.
Open: You can export your private keys into other Bitcoin clients.
Tested and audited: Electrum is open source and was first released in November 2011.


http://electrum.org/tutorials.html#why-electrum