What my initial primary purpose for getting a flash now is for club photography (such as this kind of style: http://www.snapstarlive.com/events.aspx ), which means challenging lighting conditions (a fast wide prime lens will be my next purchase after this... but one thing at a time!).

I think the most important features I'm looking for is:

a) ability to bounce the flash off the ceiling (essential!)

b) rear curtain sync (essential!)

c) affordable

d) compatible with my Nikon D50 (of course... )

Would be "nice to have":

e) iTTL

f) would also be compatible with the Panasonic GH2 (as I'm going to buy this for taking video next month, or sooner... as soon as I spot a Christmas sale bargain, was very recently going for only US$499 for the kit. I wonder if I might again see this kind of pricing, or better, soon?)

g) fast recycle

h) swivel head

i) has a battery pack option

Suggestions that fit my criteria? (and is there anything else important that I'd use which I'm missing out from this list?)

Am a little lost when looking at flashes for bargains, but it seems these would be good options:

http://www.amazon.com/Opteka-Autofocus-Dedicated-Digital-Cameras/dp/B005KA60BS/ (with this too: http://www.amazon.com/Opteka-Universal-Diffuser-Olympus-External/dp/B0017U0WM8/ yes? )

Seems to have everything I want (except I can't tell if it would be any use with a Panasonic GH2?), but I'm a little concerned about quality.

From what I've read about Yongnuo (http://stores.ebay.com/hkyongnuophotoequipment/Flash-Speedlite-Unit-/) as a non-Nikon option they seem like a really good choice, I would quite like to consider the Yongnuo 460 (the cheapest), the 560 (cheapest with an option of later getting a battery pack), or the YN-467 (I quite like that it has a reported extremely fast recycling time in the test) if they would work as that would be ideal (or from any other brand at a comparable sub-US$100 price?). However I've read in quite a few places that although the Yongnuo range for Nikon is compatible with Nikon i-TTL cameras it is not however compatible with D100 D50 D2Hs D2X D70 D2H. Hmm... why? Can I still get it for my D50?

http://speedlights.net/2010/09/10/yongnuo-yn-467-speedlite-review/ The YN-467 originally is reported not to work with certain older Nikon DSLRs but the more recently produced YN-467 models are reported to work with the D200, so would it be reasonable to assume it then works too with the comparably aged D50?

This thread mentions the D50 a few times and makes feel optimistic the Yongnuo range can work with my D50: http://www.flickr.com/groups/strobist/discuss/72157627857970265/ But they're only mentioning the YN565EX (which is almost the most expensive Yongnuo flash), would it be reasonable to assume from that thread the cheaper Yongnuo flashes should also work similarly with the Nikon D50?

Disappointed I didn't have the guts earlier to pull the trigger and buy this when I saw it: http://www.trademe.co.nz/Browse/Listing.aspx?id=543490048 As I'm realising now in hindsight that was a really good deal (even though it doesn't have iTTL).

Thanks