My favorite script right now is
Power Redirector
- Redirect based on keyword.
- Redirect based on phrases.
- Redirect based on ip address.
- Redirect based on referrer.
- Redirection based on transparent proxies.
- Redirection based on anonymous proxy.
- Redirection based on country.
- Redirection based on user-agents.
- Install site-wide or per-page.
- 301 redirects (search engine friendly).
- Free daily updated ip-to-country database.
