noob question but what are the advantages of using a flash gun over the pop-up flash on dslr cameras? i want to invest on one and would you guys recommend me a good one for my EOS 1000D / Rebel XS.
it's my very first DSLR and i'm still pretty much a noob.
I assume you mean you're typical external flash/flash shoe flash/etc... When I hear of flash gun, I think of the OOOLD type flashes
Probably the biggest difference would be power. An external flash is much more powerful than the built in flash. What really can make the difference though is if it's a bounce flash. These can be tilted to various spots to help reduce glare and provide more natural lighting.
I've compared photos using bounced lighting to direct lighting and the results are amazing. Bouncing looks so much more natural and reduces glare on objects as well as red eye.