I use ProxyPal to turn on/off the proxy setting in IE7. When I'm VPN-ed into work, I want it on, and when not, I want it off. The problem is that <Alt+T> opens my Tools menu, but there is no hot key for ProxyPal. So add one - in regedit look under the following for the ProxyPal entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extensions\
and change MenuText from ProxyPal to P&roxyPal.
Now <Alt+T> <Alt+R> will run ProxyPal as a hotkey combo.