This is probably the best regular expression development tool I've ever used. It basically allows you to build your regex on the fly without having to guess.

#devRegex Tester – RegexPal
Any character except newline. \. A period (and so on for \* , \( , \\ , etc.) ^, The start of the string. $, The end of the string. \d , \w , \s, A digit, word character [A-Za-z0-9_] , or whitespace. …

If you’ve every struggled with getting Facebook like or share buttons to view exactly the content your site has, this is the page for you.This is Facebook’s debugger tool. It allows you to see exactly what Facebook’s page scraper sees. It also tells you what it’s using for all parts of the data share and lots of advice.This is probably the most valuable tool I’ve used for Facebook sharing.Enjoy.

Source: http://developers.facebook.com/tools/debug

One of the nicest things about working with WordPress is the power of its API. When creating themes and/or plugins, the platform makes it incredibly easy to serialize and retrieve data. In fact, the API abstracts many of the common challenges of working with data such as data sanitization and efficiently retrieving data on request. Throughout the next two post, well take a look at the Transients API, why it matters, how to use it, and take a look at a practical implementation that we can use in future projects.Generally speaking, all of the above is accomplished with the WordPress Options API which is great for saving, updating, and reading options, but if youre working with a large set of data the Options API may not be providing the most optimal performance possible. Specifically, you may be able to improve the overall performance of your work (and its extensibility with other software) if you were to take advantage of the Transients API.

Source: http://wp.tutsplus.com/tutorials/getting-started-with-the-wordpress-transients-api-part-1/