what it says on the tin.
I am specially interested in swords, as most believe they used scimitars but I seem to recall that scimitars were a later invention.

In which crusade?:)
During the first crusade they used straight swords just like thier European enemies. Look for mamluk swords on google for example (but not the US Marine Mamluk sword...)
The curved blades came later as You wrote, some say that the Turks brougth it to this area. The Mamluk state confrontated with the Mongols, Persians, Ottomans, and later some French guys. So during the many crusades a crusader was able to get injured from a shamshir, a kilic, a seif, or anything You like. (theese words mean the same, sabre)


Check out this site:
http://users.stlcc.edu/mfuller/turk/TopkapiArms2.html

or my favourite site:
http://museum.velizariy.kiev.ua/turkey/istambul_ma2/index.html

You can see the tables showing the centuries.

Up until the late 13th century most "Saracen" swords were straight and double-edged. There are quite a few extant early Muslim swords in the Askeri Museum in Istanbul and they also turn up on auction sites now and again.

There have been similar topics in the past with some useful links:
http://www.myArmoury.com/talk/viewtopic.php?t=12417

oh how silly of me, the third crusade please ;P

thanks I'll look at these links :D

I have just remembered that Muslim swords from about this period occasionally do come up for auction on Hermann Historica, a pinch of salt is necessary as the provenance of some items is hard to confirm.

Have a look at these:
http://www.hermann-historica.de/auktion/hhm49...at49_A.txt
http://www.hermann-historica.de/auktion/hhm56...at56_p.txt