[piaste]

At a quick glance:

- Leta is much faster than Startpagw - Startpage offers a lot more of Google's features, eg date range filter, image search, and so on

I would guess that both differences are due to Startpage not doing any caching.

Startpage also has a neat "Anonymous View" feature where they proxy the request for you, acting as your HTTP client. If you trust Startpage, it's probably a pretty good ad-hoc anonymity tool.