Lots of folks are having trouble accessing Gmail today, and today's outage is just one in a long series of outages in our favorite webmail application. However, you don't have to let that stop you from accessing your email and getting things done. Here's how to get your Gmail even when you can't access Gmail.com.
Access Gmail Through Alternate Modes
Just because the Gmail web interface went down doesn't mean that Gmail is entirely down—often you can continue to access your account using one of the alternate web interfaces, which often are still accessible even when the regular web interface goes down.
Here's a quick look at each alternate method, one at a time, from the simplest to the most complex. (The more complex solutions are often better long-term solutions, while the simpler solutions are probably the easiest if Gmail just went down and you haven't already prepared for it.)
Try Plain HTML
Your best bet is to bookmark the link for the Plain HTML version of Gmail (or just bookmark this post), so you can quickly switch to this alternate mode if Gmail is giving you trouble loading. It doesn't have all the fancy features that regular old Gmail does, but it can do the job just fine in a pinch.
Use Safe Mode
If you use a lot of different Gmail Labs features, you might find that some of them will conflict with each other, or possibly cause Gmail to stop working. You can use the Safe Mode link to disable all the Labs features and hopefully get Gmail back up and running again. Just visit http://mail.google.com/mail/?labs=0. Some people recommend using the older version or bypassing browser checking links, but they won't let you access the Labs settings.
Use the Mobile Version
You can access the mobile phone versions of Gmail from your desktop computer, although they are very stripped down and lacking features. You'll be better off with the Plain HTML version, but in a pinch you can try the mobile version as well.
Use Gmail Offline Access
If you haven't already checked out the Gmail's new offline access, this is a must-use for anybody that really depends on Gmail access. You can continue to use your email whether Gmail is running or not, or even when your own internet goes out. It's not perfect, since it doesn't store every single email in your inbox locally, but it does store enough email to be a great solution.
Access Gmail Through IMAP / POP3
During the last Gmail outage, IMAP and POP3 access weren't affected at all, so those using a desktop or mobile client to access their email were still able to send and receive without even knowing there was an issue. Even if you use the web interface as your primary method of email access, it's a good idea to at least keep a Thunderbird installation setup with IMAP access to your email in a pinch.
We've already got you covered with a complete guide to setting up Thunderbird as the ultimate Gmail IMAP client, but since then, setting up Gmail in Thunderbird has turned into an easy process, requiring only a few clicks through the account settings. If you are an Outlook user, you can follow a detailed guide I've written to set up IMAP in Outlook 2007. If you've got a mobile phone, the Gmail Help site has instructions on setting up just about any smart phone with IMAP access to your email. If you really want to prove your nerd credentials, you can even access your Gmail from the command line.
Prepare For the Next Outage
Gmail doesn't have to go down globally for your email access to be cut off—your internet could go down, or your account could even be disabled. Whatever the case, it's a good idea to have a backup plan just in case the worst should happen.
We've got you covered with a number of methods for backing up your Gmail, starting with the really obvious solution of just using Thunderbird to back up your email with POP access, but you can backup your email with Fetchmail on Windows, Getmail on Linux, the standalone Gmail Backup tool, or even use Google Groups to backup your Gmail account.