I have a site that works very well when everything is in HTTPS (authentication, web services etc). If I mix http and https it requires more coding (cross domain problems).
I don't seem to see many web sites that are entirely in HTTPS so I was wondering if it was a bad idea to go about it this way?
Edit: Site is to be hosted on Azure cloud where Bandwidth and CPU usage could be an issue...
EDIT 10 years later: The correct answer is now to use https only.
HTTPS decreases server throughput so may be a bad idea if your hardware can't cope with it. You might find this post useful. This paper (academic) also discusses the overhead of HTTPS.