I want to have a play with film.

That's right, despite being astounded with the 400D, I want to have a tinker with a 35mm tape laced with chemicals. (I plan to cheat and take the 400D with me to set up and try the shot, and then take it on film :lol The only EF lens I have is the 50mm f/1.8, but that's very versatile... can anyone recommend a (preferably sub-GBP 100) EOS film body --- is the 3000V any good, 'cause that's a lot of digits --- or a good one to have second hand?

I bought an Elan (100) for $40.00 and fixed the main dial, buggering up the on board flash in the process. Got a steal on a Elan 7e brand new. Both work outside and the Elan is super in low light. Both are quiet as can be. Both can be had for almost nothing if you look around.

Get the AE1. It was the work horse of the early film bodies. Cheap on ebay. Has many accessories like power winder excellent lens, etc. You will remember to learn to get exposure right, being you cant PP on computor...

AE-1 great camera, but you have EF lenses. If you just want one lens, then it won't matter. Lots of lenses to be had for cheap, but then if you want to take both systems....
Just something else to think about.

The Elan 7 is a great EOS film camera. It's much better than the rebels and can be had for less than $100 US used so probably significantly less than GBP 100. It might have a different name over there though.

Eos Elan 30 or 33 your way probably. One has eye control and one doesn't. I haven't messed with it much. It was a better price at the time than the non eye control was.

Personally I would take my A-1 over 2 AE-1 bodies...

If you just want to mess around, the FD bodies are really nice for shooting film. You could realistically pick up a decent FD body and a 50mm 1.8 for less than a cheap/decent EOS body.

If you had a bunch of EF lenses, I would probably encourage you to get an EOS body, but with only the 50mm, I personally think you would have more fun with an FD body. You can get a couple basic lenses for it cheap as well.

I LOVE my A-1. They go for a bit more than the AE-1, but it's a VERY nice camera, and can shoot Av, Tv, or Manual.

Braduardo is right. I didn't realize the Tammy was for 1.6 cameras only.

I second manual focus SLR or rangefinder too.

There's no reason for you to get an autofocus camera body. There's a lot of cheap good glass can cameras for film. The viewfinders and the experience is... at the very least different and IMO "better" than shooting with canon AF.

You'll hate the rebel's viewfinder afterwards.

Examples:
Canon FTb with 135/2.5 - 40 bucks
Olympus 35 RC - one of the smallest coupled viewfinders in the world - 25 bucks
Canon Canonet QL17 -20 bucks

Just keep in mind that bodies are cheap.
50mm lenses are even cheaper - as low as 10 bucks. So don't let the 50/1.8 steer you into canon AF.

There's no rule that says that all of your lenses have to be from the same manufacturer. Sometimes I buy a good lens first, and then buy a cheap body just to be able to use it. So one could end up with a nikon, canon, pentax and olympus... and only have one lens per mount.

I just bought my 12 yr. old son an Elan II (50) to learn photography. I got it for the unreal price of $25.00 USD on eBay. You'll find tons of them there, it takes EF lenses, and they are quite capable.

I've been using my trusty Elan 7E for years and it is a great SLR camera. I really like the ability to choose the focus point by looking at it. I have always wondered why DSLR's cant do that?

I will always enjoy shooting film.

Ride to live, live to shoot.........

Second the EOS-3 or Elan. Maybe EOS-5/A2. The Rebel Ti/300V and T2 aren't bad but I'd avoid the cheaper Rebel models like the K.

I have a mint A-2 sitting in the closet, could probably let it go for 75 bucks.

I still have my old AE-1 and all the Canon lenses & accessories I had back in the late 70's .. and I wouldn't part with them. The quality of the equipment (and the photos it takes) are superb. I picked up a mint EOS3000 so I could use my EF lenses, but it hardly gets used these days.
Given the choice I would say go the manual focus route .. you'll appreciate taking great pictures more that way. Buy a decent body and don't skimp on the lenses.