Francisco is right. If it's just fill-flash you need, a pocket flash is probably all you will need.
I use the 544 because I sometimes need a powerful flash to light up a room. My wife's family is rather large, and a holiday group picture can be 35 or more people. I also want to do individual portraits sometimes, and Sunpak makes a portable umbrella that folds up into a tube the size of a 3-cell flashlight. It fits on the 544's filter holder.
I wanted one flash to put in my luggage that would do everything I need to do on a family gathering. Since I use older cameras like Mamiya C33's and Nikon F's, I didn't need hotshoe capability.
An even better handle mount flas than the Sunpak is one of the Philips handle mount units. they have been discontinued and can be found on e-Bay for anywhere from $10 to $50. Search under both Philips with one L and with 2 L's. They are just as powerful as the Sunpak, are smaller, use only 4 AA batteries instead of 6, and best of all, have automatic exposure even with proportinal power (automatic 1/16th!) The Sunpak won't do that. Don't pay too much.
When I just want a small pocket flash, my favorite is a Vivitar 200, also discontinued. They sell on e-Bay from $2 to $20. I like them because they have a 4-5 second recycle time using a 9-volt smoke detector/transistor radio battery. I keep one in each of my camera bags.
<a href='http://www.rangefinderforum.com/photopost/showgallery.php?cat=500&ppuser=117'>My Gallery</a>