Using User Agent Switching Tools for web design

Hey guys!
When you're building websites, it can be pretty useful to identify the user agents of the devices viewing your content. Now that we are in 2013, the number of mobile devices with internet capabilities are growing tremendously Although there are other methods of identifying the user (such as by a device screen size identifier) user agent detection can also be pretty handy. Today I want to introduce a few nifty tricks for testing out your site in different environments, all within your browser window. You can also use these tools to view your website as Search Engine robots would, although I am not going to go in-depth into that today.

The User Agent Switcher tool is part of Chrome’s Developer Tools, and is built-in. Also that's the case with Internet Explorer's built-in user agent switching tool.
Youcan find the Internet Explorer user agent switching tool, when you navigate to the Developer Tools (F12 shortcut unless you have set it as something else)>>Tools>>Change user agent string>>"Select User Agent of choice here"
You can even add some Custom User agent identifiers.
NoteI should point out: don't get user agent tools mixed up with IE's Browser Modes tool!! Browser modes actually shows you CSS based on different browser rendering types and their level of CSS support (or lack thereof....Yes, I'm talking about you IE6/IE7/IE8). The User Agent Tool actually makes the website think that you are a different user agent so if you tell the website you are an iPhone, it will show you it's iPhone-specific site, or Android or anything else.

Surprisingly, Firefox doesn’t have a built-in interface to do this, but your best bet is to use the "User Agent Switcher Add-on" which you can find in the mozilla addon website.
You can download User Agent Switcher for Firefox here.
When you do have that, you can navigate to : Tools>>Default User Agent>>"Select User Agent of choice here"

You can play around with these simple tools, and it may speed up your testing tremendously, although I would recommend testingactual for production websites.

By switching your user-agent to Googlebot, you will essentially see your site in the same eyes as Google, so if there is a Google specific flaw, some cloaking going on, or possibly even a Googlebot targeted hack, switching to user-agent Googlebot will help identify these issues.
In Developer Tools of Internet Explorer, there is another feature to change the mode of Browser, by which it can switch to older versions of IE, like IE8 or IE7. By using this feature, you can switch the browser to an older version to see how a webpage is rendered in an older browser.