I use this one

http://cgi.ebay.co.uk/Portable-Ultrasonic-Nebuliser-Brand-New-and-Unused_W0QQitemZ180402147236QQcmdZViewItemQQptZUK_Health_Beauty_Mobility_Disability_Medical_ET?hash=item2a00ce4fa4&_trksid=p3286.c0.m14

and swear by it. It's really quiet and I use it at the first signs of a
cold/flu etc. It nis it in the bud and i wouldn't be without it now.

Cheers
Kirsteen