There's an easy way out for you. Google has recently rolled out 2 step verification for all google users. It is pretty straight forward. What it does is, it links your gmail/google account to a mobile phone number.
So the moment you want to log into Google, it will send you an SMS with a 6 digit code which you have to enter in order to access the account. Since you are going to configure this is service for your mobile phone, you can be assured that no one else will get access to your account.
Here is a link about this
http://googleblog.blogspot.com/2011/02/advanced-sign-in-security-for-your.html I have been using this method for quite some time and it seems pretty cool and since the SMS service is does not affect your mobile phone bill.
The only flip side is, you cant lose your mobile phone and it might cause you problems if you travel overseas and not have international roaming since google will try to send the code to your phone.
But all in all, its pretty unsafe, surfing with a dongle as opposed to doing the same behind a route with a hardware firewall. But a practice I use is, use a user account without admin rights when accessing the internet directly.