Bumping an old thread to add my $.02

Storing your seeds online is no good. 

I personally use lastpass for all my passwords.  The data are encrypted client side and never transmitted or stored unencrypted on Lastpass's servers.  They were hacked a year or two ago but the databases storing the encrypted passwords were not compromised.  I believe they only got user information.  Lastpass caught the hack themselves (either in progress or shortly afterward) by detecting an abnormal traffic pattern between some of their servers. 

So while I trust my encrypted passwords to lastpass, I don't trust the clients that decrypt those passwords (including my own computer) with my seed.  There are vulnerabilities in Lastpass clients that essentially trick the lastpass extension into filling hidden form fields on a website with all your passwords and posting them to their server behind the scenes.  This may be fixed already, but it doesn't mean another zero-day exploit won't be revealed in the client that can do the same.

Don't trust your seed to an online computer if you care about the BTC that the private keys can access.