Notifier2 is a free windows program that allows you to monitor your multiple email accounts without having to log in. It sits obediently on your task bar and keeps a tab on your accounts. You can monitor multiple GMail, Hotmail or Yahoo accounts. Notifier2 also provides a preview for your email accounts. Only log in if you see some important emails come in. You can also send emails in 2 clicks using Notifier2 as well as use Google Talk, store files online, and manage content across accounts.
The free version only checks email every 15 min and checks a maximum of 4 accounts, the $9.99 version eliminates these restrictions. Imagine all the surfing you can do instead.