What is the cheapest flash or strobe to use ?

I presently use a JTL S-25M slave strobe with my Fujifilm S5000 digital camera as they are cheap and work well. When I am at graduations and other functions other cameras flash send of my slave at the wrong time. This is a big problem. Name me a cheap flash or strobe that will will only be triggered by my new Nikon D40 camera (even if it has a slave feature). My light stands are still fine.What is the cheapest flash or strobe to use ?
Slaves that fire whenever a flash is detected really only work in a studio environment were your flash is the only flash that can be detected. Outside the studio, something like a PocketWizard is the way to go. If you find the older transmitter/receiver pair you can save some money. The new ones are transceivers which cost a little more. Put one transceiver on your strobe and the other in your hotshoe. Find a channel no one else is using, and you've guaranteed your slave only fires when you want it to.





The cheapest solution would be to connect it via a PC Sync Cord. The D40 doesn't have that port, so you'll need the Nikon AS-15 Sync Terminal Adapter.What is the cheapest flash or strobe to use ?
Try the Flashwave:


http://www.g9chon.com/





It's about $210 for transmitter and receiver.





The next solution: an SB-600 flash, about $178 from buydig.com and then an SB-800 to put in the hotshoe (about $320). The SB-800 will work as a ';commander'; flash and the SB-600 will work as a remote flash with TTL capability. Take the special tripod adapter from the SB-800 kit and use that to put the SB-600 on your light stand. A bit more expensive, but you'll get wireless TTL that won't be triggered by another flash (unless they are using the same channel as your SB-800 and you have several choices to avoid this).