At GBJ we've used Zapier with a number of projects including Lightning Lab where we used it to connect multiple web based systems. It's a fairly impressive app that can glue together multiple independent systems.
Zapier lets you make something happen in one system based on something happening in another, for example; add a row to a Google Sheet when a new eventbrite registration happens, create a new Trello task when an Evernote note is created, create a Mailchimp subscriber when an entry is added to a Google Sheet etc. Check out other popular use cases.
They have just released 2 massive updates; multi-step zaps and code steps. These two updates enable Zapier to be much more powerful. These are massive improvements to the product which we are looking forward to use in upcoming projects. If you have used Zapier recent for an interesting task we would love to hear from you.