Next, Google will ask you to provide the phone number of the device youd like to use. Its understandable if youre hesitant to give out your phone number, but note that Google promises it will only use this number for account security. You can provide a landline or a cell phone number, and you can choose whether Google should send codes to that number as text messages or via a voice call. (Note: You really shouldnt use your Google Voice number, since you could get stuck in a Catch-22 situation where you cant access your Google Voice account to get the code you need to log in to your Google Voice account.)

After you click to proceed, you should receive the text message (or phone call) within a few seconds. Type that code into the webpage and click to continue. At this stage, youre nearly done with the initial setup. Google will want to confirm whether it should trust this computer. That setting is a bit misnamed; essentially, if you leave it enabled, logging in to Google on that Mac with that browser wont add the second step for the next 30 daysunless you delete your browsers cookies.

Now, just when you feel like youre finished, Google throws up a gotcha: Some apps cant support verification codes. If you use a third-party email app to check your Gmail account via POP or IMAP, for example, that app wont be configured to prompt you for the second step code.

Thus, for email appsand Google Reader-using apps, and Calendar or iCal, and so onyoull need to configure special, one-off passwords instead. You can generate as many of these so-called application-specific passwords as youd like. You provide a label (for your own records), like, iPhone Mail, and then Google presents you with a 16-character password. You can never retrieve that password again, but it doesnt matter. Dont bother jotting it down. Copy and paste it (or painstakingly retype it) wherever it needs to go, and then click the Done button.