We have recently been asked to jot down a few website extensions and updates that we have implemented recently.
Screen Pages has a team whose sole purpose is to extend existing websites - fundamental to our approach of creating bespoke websites, but the trick is to develop modules that can be easily re-deployed on other clients (in the spirit of cooperation).

Here's the list and links (where appropriate):
* Paypal as an alternative payment provider on the Thorntons website
* Renewal tool for regular products (customer is sent letter with unique code which preloads previous purchase for easy repeat buy) for Smythson diaries
* Cybersource as an online payment gateway for Harrod Horticultural
* Peerius recommendation engine for Smythson (automated, targeted x-sells)
* Guest checkout for various Magento websites
* Review booster (automated email to request review) with cross-site review displays
* Colour-coded microsites on Party Pieces
* Filtered navigation for various Magento websites
Our last list of website updates is here.