I want a bluetooth earpiece, for occasional use - basically for driving
really - and have been searching ebay.  Two queries:

1. The vast majority (certainly the cheapy ones) seem to have a large
earhook, which surely is going to interfere with the side arm of my
spectacles - correct? Isn't this a big issue for specs wearers?

2. Some models seem to claim to be compatible with anything, others are
mobile-specific.... what's all that about? Isn't bluetooth supposed to
universal?  Mobile's a not-particularly-popular Nokia 5500.

Was hoping to spend no more than around 15 quid...???

Thanks
David