We actually did a review of the Seidio headphone adapter here on our website.
You will find that when you get a call you will hear the audio on the headphones. If you do not purchase the adapter with the mic built in then you will have to disconnect the headphones to get the mic to work on the 8800. I cant promise for other phones like the 8100 what would happen since I do not have one. The other option is to get the Seidio headphone adapter with the mic but I personally found the mic to be so far away from the headphones that it was useless. You can check out the mic one here:
http://www.seidioonline.com/index.as...ROD&ProdID=517
Personally If you feel ready to try something new you may want to try the new shure headphones with built in 2.5mm adapter. I'd be curious to see how that would work