Google has announced the addition of a new feature to Gmail which will make it easier for you to switch between your accounts. Now,
you do not need to log in or out from your accounts in order to switch.
The new feature has been named, "e-mail delegation". With the help of this feature, you just have to login to your primary Gmail account and grant access to your other accounts. You can do this by going to Gmail setting. Gmail now features a new tab 'Grant access to your account" under its Account function. Once you have followed through the entire procedure, you are all set to toggle between your accounts.
If you are signed into your secondary account and you send a new mail message then such message will also feature your primary account. So probably that's where you need to be careful if you do not want to reveal your primary identity to the people you correspond with using your secondary email accounts. But overall, the new feature sounds like a good addition. Let us know about your views.