We’ve wanted this for ages, and our requests has been answered. According to the Twitter blog, the site has finally added a Follow button:
For publishers and brands, adding the Follow Button to your website and using Twitter to stay connected with your audience is a powerful combination. People who follow your account are much more likely to retweet and engage with your Tweets, and to repeatedly visit your website. Adding the Follow Button to your website is quick and easy, and you can configure yours right now at twitter.com/followbutton.
The follow button is being launched on 50 blogs around the Internet as of right now. If you want one for yourself, it’s incredibly easy to do. Just head to the link mentioned above and fill in the form. You’ll get a box of code on the right which you can then copy and paste into your desired location on your site.