Headset for iPhone 4

I will greatly appreciate reviews and comments on what wireless headset you are using with your iPhone 4. I see them ranging from $40 to $200. I just want something that will serve its purpose and work well. I don't care about flashy or brand name, etc. Being unemployed, I don't want to spend more than I need to. Thanks in advance for your help.

I am using Blackberry HS-655 Bluetooth Headset with iPhone 4.
I am very happy with it, goes well with the iPhone.