Got my Klipsch image s4i few days ago after few weeks researching for an earphone to go with my iphone 4. I got a green light from my friend on this product. (He's a music teacher, uses shure 530) so I hope you guys can check it out =D
I choose this because it has a built in microphone, dedicated buttons like the stock apple earphones to navigate your music through
Won cnet choice award too.

http://www.youtube.com/watch?v=oXtnPRid61w

The Koss iSpark is a budget stereophone with good sound quality, noise isolation and a barely  decent microphone. Sadly the design is poor to the point where I would like to call it broken. I can not recommend the Koss iSpark to anyone.