Sure, there are a number of alternatives, but the first that I would look at (since they have gotten much cheaper) are powerline adapters. You can get a pair of 200Mbps or 500Mbps (they perform about the same) for $50 or so on sale and they work pretty well if your house is less than 30 years old.
Plug one in near his computer and one near your router -- just avoid plugging them into a power strip and don't have them on an outlet with a strong motor (like a fan) unless that motor device is on a 6 foot extension cable -- that moderates the interference very well.
The other alternative, if he has a good wireless signal near his computer is a USB wireless adapter (assuming you have wireless from your DSL router). I use several of this model and they are quite good: http://www.newegg.com/Product/Product.aspx?Item=N82E16833704045
The best way to check for his wireless signal quality is to download and install inSSIDer (a free program) on a laptop and run it from where his computer will sit -- if you get a good signal, you can use the wireless adapter.