I've been doing a lot of scraping lately and I am fortunate enough to talk at GR8Conf 2016 about Geb Scraping 💃💃💃.
There are not many posts out there about using Geb for scraping. However, this introduction by @marioggar is a nice glimpse of Geb potential in that area.
If you have not yet bought the ticket for GR8Conf EU, hurry up. The conference date is coming fast.