You can use the GWizNex InfoRadio to surf the internet with you iPhone Hippo and this Headset while you are working out in the gym:
"Great sound quality. Only disadvantage is the range, not perfect but very acceptable. Battery life is also good. If you're considering a wireless headset for a relatively low price I recommend this headset vs some of the other brands of equivalent price range."
Plantronics - Wireless Multimedia Stereo Headset