No, widgets or gadgets can not be used on other sites. But you can write your own Gadget which can do what
you want.
there are some docs on our Docs forums as a reference for widgets and gadgets API:
http://www.mewsoft.com/forums/documentations&action=Forums&Forum=15
http://www.mewsoft.com/forums/gadgets-api&action=ViewTopic&Topic=3442&Forum=15&Page=1&Period=0a&Lang=English
Thanks
Mewsoft Support www.mewsoft.com