Recommended GPRS device

Hello all,

I'm working on a weather station and I want to hook up my Arduino UNO to the internet. The only thing that I need to do is going to a certain url like http://www.myserver/temp/wind where temp and wind are parameters. What would you recommend that I buy? It can be a shield or something that I can wire up, anything goes, I just need to be able to visit urls.