HTTPS Everywhere
When creating a new website you should always use HTTPS. Here's a video recorded at Google I/O earlier this year on the why and how.
The New York Times switched to HTTPS last month. Here are their reasons for doing so:
Best Practices for Using the Vary Header
Vary is one of the most powerful HTTP response headers. Used correctly, it can do wonderful things. Unfortunately, this header is frequently used incorrectly, which can lead to abysmal hit ratios. Worse still, if it's not used when it should be, the wrong content could be delivered.http://www.fastly.com/blog/best-practices-for-using-the-vary-header/
