used my friend's yn-560 for a while. totally worth it. if you're considering getting into flash photography, get it. it's super cheap, but is a great working manual flash. i know the strobist praises the lumopro lp-160, which is what i bought for myself, but honestly the yn-560 is just as good, even though its guide number (how strong it is) is just a little bit lower.
there is also a 560-ii that is coming out soon or is not out yet, but BE WARNED. though the ui is much improved from the 560, there is no backlight to the digital screen, making the screen near useless if you're shooting somewhere with the flash and there is no light. in my opinion, get the 560. not the 560-ii.
and tthx has a point, ettl DOES come in handy, but using a manual flash gives you complete control over what you are doing with your light. even if i went pro i'd probably use a manual strobe. hell, most (to my knowledge) modeling lights are manual anyways so knowing how to perfectly control your light will become important if you get into that.
in short. get the 560. i HIGHLY recommend it. and if you hate it, you're not out that much money.