I don't know if this is the proper forum for this topic, but here goes...

I'm new to both HTTPS and VPN's (virtual private networks), but I just read some articles that intrigue me. I associate HTTPS with secure transactions - like online shopping and application forms that require personal data.

But there are apparently efforts to promote HTTPS for general websurfing. There's even a Firefox HTTPS addon.

I'm also experimenting with a VPN. It's very easy to use, even though I still don't fully understand how it works and what it can do. But my perception is that HTTPS and VPN's both increase security, and the two combined should be even better.

So what do web designers think about these technologies? Do you just use them for online transactions, or do you think it would be appropriate to convert ordinary websites to HTTPS? And how do you make a website HTTPS-compatible in the first place?

Tentatively, I'd like to be able to offer my visitors two choices: "Surf this site in HTTP mode or HTTPS mode." If they choose, the latter, then http://www.mysite.com/cool would automatically default to https://www.mysitecom/cool

How can I do this, and is it a good idea?

One problem that occurred to me is that, if my visitors are using VPN's, then my site presumably wouldn't recognize them as return visitors, wouldn't remember their passwords, etc. That's not a huge issue at this point, because I still haven't set up any of my sites with visitor registration or that type of thing.

Any way, I'm shooting in the dark and would appreciate any comments that might help me understand HTTPS, VPN's and their relevance. Thanks!