our little grey kitty is sick-anyone a vet?

[CremolaFirCone]

3 year old cat has vomitted once this morning and has been shakey all day.trembling and a bit lethargic- like moving in slow motion.his eyes are not dilated or weepy and he has eaten some crunchy kitten food and water. really do not want to bother the vet on a sunday if not serious.he has fallen asleep on dh now and his breathing and fur seem fine.
can't find anything about trembling in my cat books.
any help gratefully recieved,

could be worms
try bland food water and brushing see vet if not better by mon

thanks galaxy.he was wormed recently.but will take your advice with the diet and get dh to brush him on his knee.

Has he had a wee today??

oh thanks casper. he seems much better today.no more vomit and he has been out for a while as well.his eyes are shiny and he has had lots of water.
i think he probably tried to eat something horrid- he is a real hunter for mice and wee birdies so that i think is the most likely explaination.
i was worried that he had been bitten by another cat or had an infection.
thanks for all the replies- it really put my mind at rest.
hopefully he will continue to pick up.