I got tens of custom templates in english language but I just tried to add a french template of same site using
STSADM -o Addtemplate -filename -title
then did a IISReset, but when I go to Central Admin or try to create a new site through Site Actions I am not able to see that french template I just added, am not sure what could be the reason other then language pack ? but I did had french websites on same Virtual PC before which I can't find anymore.
Oh yeah I can also find/see that template if I do something like
STSADM -o enumtemplates -lcid ****