Good point magpie -
Having something to bridge between the socket that you are trying to protect, and all the inserting-uninserting you might be doing will only prolong the life of your equipment. Now, the mini 2.5mm Y splitter 'may' degrade the quality of the sound a tiny bit, it is barely noticable. If you are truly paranoid about having 1 percent less quality, stick an inline amplifier between into the mix
(thanks to charliex for remind me about the inline amplifier in another thread)