Nikon and canon camera flashes?

I'm looking tours buying a camera flash for my canon XS (1000D) but i wanted to know if there are other brands like nikon that also sell some very good flash and and do they work with canon cameras like the canon XS (1000D)

Other than studio strobes triggered by sync cables and optical/radio slaves, flashes are generally brand specific. Major brands like Canon and Nikon only make flashes for their respective camera/lens systems rather than each other. While I'd recommend sticking with Canon flashes for your Rebel XS; Sigma, SunPak, Nissin and Metz are all companies that make well regarded alternative units configured for either Canon or Nikon.

The third party options are sometimes cheaper but, usually you give up something for that price. Occasionally, third party options are actaully pricier than even Canon's own speedlites. Be sure to compare models thoroughly before your buy and remember that only Canon speedlites can be controlled directly from the camera menus.

You have a canon, buy a canon flash, ex speedlite. The 430 is the most versatile, most fully functioning, most powerful bang for buck of Canon's speedlite series. Tilt swivel zoom head, LCD screen, camera menu control (on the 430EX II) works great with EOS1000D's E-TTL-II metering and allows cool things like 2nd curtain synch (useful for fast objects) and high shutter synch (great for daylight fill flash)