Or better still check out BiteSMS, which can get rid of popups along with some great other features (compose/reply from within any app or the lockscreen; custom SMS tones, etc) or Lockinfo, which gives you a pull down notification like Android or iOS5 for SMS, email, calendar, notifications, etc...either one can help you do what you want AND make it easier for you to see your incoming texts.
(And if you buy Lockinfo, you get a free Pop Up Blocker license included.)