At Defcon, I bought an EVDO antenna from one of the vendors for $30. The dealer stated that I could see up to 2x the upload and download speed. After doing tests in a few cities, I can say that the antenna does increase speed.

Here are the results from my tests:

• Las Vegas – 44% increase in downloads, no change in uploads.
• Dallas – 30% increase in downloads, and a 39% increase in uploads.
• San Francisco – 60% increase in downloads, and a 44% increase in uploads.

While my tests didn’t result in doubling the speed, it did provide a decent boost. And because the antenna is relatively small, I take it everywhere now. Highly recommended for any EVDO equipped road warrior.

Update: EVDO City is selling a product that looks identical to the one I bought.