[Terry Porter] added an external antenna to his EeePC 900. Initially, he mounted it on the side of the unit, but found that the location caused it to no longer fit in its carrying case, and made plugging in USB or Ethernet cables very difficult. His resolution was to move the mount to the rear portion of the case. His professional looking mount is definitely worthy of some attention. Check out the project for a breakdown and some great pictures showing the necessary modifications to make it fit.
If you’re going to crack open your EeePC, you may want to just go all out and add everything available.