Gameboy Advance SP - headphone/charger splitter?

[Jorpho]

I was thinking about this again recently. Has something better-constructed and more readily-available materialized in the last two years?

I did find http://dx.com/p/2-in-1-rf-stereo-wir...dvance-sp-4491 , which looks like you can plug in a charger and headphones simultaneously, but it's impossible to tell – the headphone jack might only be for the built-in radio. Also, it's sold out.