Archived from groups: alt.comp.networking.connectivity (More info?
What you're looking for is called a Wireless Repeater or a Wireless
If you already have a second router, you can do what Jonathan said and
check if it can be used as a bridge.
The device I was talking about was designed specificaly for your needs,
so setup should be a breeze.
Another way to go would be to get a bigger/better antenna. If your
router has a detachable antenna, it's something worth looking into.
Hope this helps,
Noam Nelke, Israel.