I measured the ecplise mints case side by side with a Altoids gum mint and the eclipse case is bigger in all aspects. Plus no dent means even more usable area.
Hair: Seeing how the Mini Minty is mostly dip or larger smd parts, it might be possible to find compatiable parts in smallers smd factors (Which means I'm going to have to work completely from the schematic). Same goes for the cMoy, which I have been able to make very compact. Plus the combo means one (or two depending on how you look at it) less auido jack to deal with, as mini minty audio out goes straight to the cMoy audio in. Add a pair of mini dpdt toggles to switch between the cmoy and fm transmitter and power, and I should be able to include everything on the same board (maybe even circuit depending on the parts used). It will be made to go into the Full sized altoids or penguin mint case, maybe the newer cigarrette metal cases from camel (Image: http://whyquit.com/Youth/POS/44.jpg
) which are are not as deep, but wider and longer then an altoids tin. Ohh, and smoking sucks, so don't smoke.
And about the volume switch, it only acts like an on/off switch if you buy one with 5/8 pins mono/stereo. It needs to be made to work like both. Personally, I prefer digital volume control via buttons, which I am implementing in a cMoy once I get the sample from maxim.
Backass: like Ladyada has said on Minty's page, "Very low power only a few mA, so I didnt even put in a switch for it." The fm tansmitter doesn't need a switch, but it might be a pain to have to switch the frequency if you "mistakenly" interrupt someone elses radio. But if she doesn't add it, its quite easy to add a switch, schematicly speaking. If you buy a premade board, its alot harder. And if she doesn't add the transmitter at all, it works as a seperate circuit, not hard at all to make or add (four connections to Ladyada's board, one to V+, another to V-, and one connection each to audio out left & right)
IMHO, there's no reason not to add the fm transmitter since it has low power consumption, small uncomplicated circuit, and its smd profile. But then again, I can't design a DIY mp3 player.