That really doesn't sound too good! It could be a whole range of things, such as congenital disorders, a virus, or an adverse reaction to some type of chemical. It sounds to me like it could also be some type of nervous, cardiovascular or ear disorder. Keep her isolated from all your other pets.

Let's hope it's the ear - it is the least harmful. Pixel was doing things like that when her ear was infected as it seriously affects their balance.

There is probably an emergency vet somewhere in your city - try looking up all the vets in the White Pages, try the local pound or other shelters as they often have 24 hour care ... I know that here in Australia, the RSPCA (like the ASPCA) has a vet ambulance and 24 hour care. Inner city vets are often 24 hours also.

Good luck. Try and keep kitty warm and dry as much as possible.