Thought I'd share this to encourage those of you who don't want to spend $500+ on a wireless system. My group in Taos has recently had great success with this, a handheld mic system for just over $100:
Audio-Technica ATW-802 VHF Wireless Microphone System. http://www.fullcompass.com/product/420660.html It is available in 3 fixed frequencies (not switchable), so it won't work for everyone. I recommend buying from a local retailer if possible so you make sure it fits your needs and can easily return it & try another frequency model if one has interference. Because it is set to a fixed frequency, this system may not work well everywhere, especially in urban areas. The quality is good so far (4 successful months & counting, on same pair of batteries even), though user must be very careful not to switch the wireless system off while PA volume is up, as it makes a loud and horrible noise. We also prefer handheld to headset for variety of uses and sharing reasons, though headset would be handy at times. Nate