Pronunciation: Comparison Tongue Twisters

I have noticed that there are very few resources on the web dealing with comparitive pronunciation. I have used these in different language groups and have had success. You can use them as a warmer, as a cool reward game or as a lesson. Try breaking the students into groups and getting them to have a 'war' to see who is best.
'R' vs 'L':
Really leery, rarely Larry.
Red lorry, yellow lorry.
A lump of red leather, a red leather lump.
All roads lead to Rome.
A loyal warrior will rarely worry why we rule.

'Th' vs 'S':
Three thirsty singers are thinking about saying things that are sensational. They might say that these sentences are not very good, but I think they are great!
These things are thick with jam. I don?t think that I like jam. It often sticks in my throat and makes me sick.
Thirteen thin and thoughtless men were seeking some thistles in the field. They were very thorough, though they only searched on Thursdays.
These thick thieves were slipping and sliding along the ice when they were threatened by three thunderstorms. Then they ran to their thrones.
In order to thrive in Sweden, you must be thrifty with the theatre tickets. They will only be sold on a Saturday or Sunday, theoretically.
During Thanksgiving, it is very important to thaw the turkey. Then you should use a thermometer to check the temperature. It should cook at about 350 or thereabouts.
Thankfully, the thinkers are seeing to the problem themselves. That way we don?t have to say which theory is best.

'V' vs 'W':
Very well, very well, very well.
I want to go to Vietnam for winter vacation.
I wish I could be a vampire from Vermont.
With velvet veils I washed my velour windows.
This veal is very Western.
There are no white vegetarians in western Venezuela.
The Victorian wicker furniture is in the vicinity of the water fountain.
Velma, the violent villain is waiting and watching vigilantly.

'R' vs 'W':
Wow, race winners really want red wine right away.
Reed Wade Road.
Way rewound.
Real rock wall, real rock wall, real rock wall.
Willie's really weary.
Ripe white wheat reapers reap ripe white wheat right.