[chrj]

It shouldn't matter if you are using GET or POST - how would your ISP find out anything about your request if you are using HTTPS?

[Yrlec]

You are correct, I was drawing the wrong conclusions from how the HTTP headers are sent. It doesn't affect how much info the ISP gets. However, POST parameters are somewhat more secure, since less info about your query is cached by your browser: http://stackoverflow.com/questions/198462/is-either-get-or-p...

[arnoooooo]

POST parameters also usually won't show up in logs, unlike GET parameters.

[dotmanish]

Whose logs?

[Zikes]

Web server logs typically don't record POST parameters. It's possible that the web server could record them anyways, though.