A couple of times this week there has been a long haired tabby hanging around our garden. Last weekend I thought it got stuck on our flat roof and so let it in via a window and then showed it out the door. Today I was out in the garden with the kids and heard the same pitiful mewing, and there was the cat up in a neighbours tree. Again I thought it was stuck (hence the mewing) but it managed to get itself down. It looks quite thin so I gave it a sachet of food which it wolfed down, so gave it some more food and it wolfed that too.

It has a pink collar on so it belongs to someone but it didn't want me to touch it; just sniffed a bit at my hand.

Any opinions/advice on this? Could it be a lost/abandoned cat? How do I go about locating the owner?

Sorry if these sound like obvious questions but I've not had this before.

(Have my own cat so adopting the stray, if that is what it is, isn't something I could do.)

Sounds like she has an owner, but is a little mare!!

My Stripe has three homes in addition to ours (that I know about!!) and she acts as though she is starving in all three!! Then comes home and has a bit of the food we put out. One thought she was a stray, one just love her, one thought she was underfed She is a right heffer!!

You could try attaching a name barrel to the collar with your details on - the owners will probably call you PDQ

Good suggestion from stress monkey, or just a note asking them to contact you to confirm it isn't a stray. You could also ring round local vets and rescue societies etc to see if anyone has reported it missing, though sometimes they can have got lost from some distance away.
If it gets tamer and you can handle it you could take it to your local vet to be scanned in case it has a microchip which should be registered with the owner's details. The vets I know don't charge for this but may be best to check that with your vet first.
Good luck with your new pet
I know you said you can't take it on but does it understand that?

Well my husband woke me up (I'd gone to bed early as felt unwell - not swine flu lol!) to say the cat was back and had come in thru the cat flap and was eating our cat's food. Our cat is a nervous cat anyway but this has made him very unhappy and unsettled. Told Mr Python to put cat food outside in the back garden for "stray".

Don't think I can put a note of sorts on the cat collar as cat is nervous - it was shaking last night - and won't let me touch it. Have done some posters to put up in local shops and will do a mini leaflet drop in local area to see what comes up. As it's the weekend will have to wait until Tues now to phone vets/rescue centres but maybe by then an owner will have come forward.

It's a lovely looking cat, very pretty, but has got bald patches too so it does look unkempt......

I'll let you know how I get on. Thanks for the advice guys!