Slow connection to my particular brand of router over WiFi with Lion on MacBook Pro
Have you tried flushing the DNS cache? In Terminal.app, enter dscacheutil -flushcache.



It could be your DHCP router handing out IPv6 information incorrectly, which is especially annoying if you don’t need IPv6 — like at home. This seems like the most logical explanation, given that all browsers and applications are suffering from the speed issues.

Go to System Preferences → Network → WiFi → Advanced → TCP/IP and set “Configure IPv6” to “Link-local only”.