Actually I was wondering about that, the dietary rules I mean. With Muslims the meat should be Halal, with Jews Kosher - but would Kosher meat be Halal as well?

Don't take this as Gospel, but here's what a Muslim guy said to me:
In order for meat to be halal it must meet certain conditions. Among these are:
(1) The animal must be killed by having its throat cut, and must bleed out.
(2) The animal must be killed by a "man of God"
(3) The man must recite a prayer, including the words "God is great"
(4) Of course only certain animals qualify e.g. no pigs

These conditions are very similar to preparing Kosher meat.
Some Muslims will accept that a devout Jew can be classed as a "man of God" some won't.
Similarly, the formula for the prayer may or may not be regarded as within the specifications laid down.

The guy who told me this explained that he himself was not very strict in observing the dietry laws. He would not eat pork, and would make reasonable efforts to get Halal meat when available. If Halal was not available, he would take Kosher in preference to "normal" (frantically seeking a word meaning "that which is neither Halal nor Kosher").
However, he would eat meat in restaurants ar at the houses of non-Muslims, even if it wasn't Halal.