IE Connection Limit

http://support.microsoft.com/support/kb/articles/Q183/1/10.ASP

The HTTP 1.0 specification allows for 4 concurrent connections from a browser to a web server. HTTP 1.1 decreases this to 2 concurrent connections, which basically means that up to 2 files can be downloaded at the same time. The more images on a site, the longer it can take to download all of them because of the limit in how many connections can be established. You can tweak the maximum number of connections for Microsoft Internet Explorer by modifying a registry entry, though you are breaking the rules a bit. Some web servers are configured to throttle the number of connections, so it may not work entirely, but it could speed up your general surfing ability. The downside is that on slower Internet connections, you'll have more files downloading at the same time, possibly resulting in slower overall surfing, so it may be not for everyone.

HKEY_CURRENT_USER \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Internet Settings

HTTP 1.1 Servers:
Value Name: MaxConnectionsPerServer
Data Type: REG_DWORD
Data: 2
Notes: 2 is the default, suggested max of 8

HTTP 1.0 Servers:
Value Name: MaxConnectionsPer1_0Server
Data Type: REG_DWORD
Data: 4
Notes: 4 is the default, suggested max of 8