ME-115+PB-B01: i.Trek Universal Bike Motorcycle Mount with Swivel Joint for iPhone 5/4/4S Samsung Galaxy S2 S3 Note 1/2 HTC One S/X EVO 4G Droid Incredible 4G Motorola Razr Nokia Lumia Android Windows 8 Smartphone (device width min 1.75" ~ max 4.25")
This mount works great for holding my iPhone.  No worries about it falling out.  However I have handle bar extensions on my Honda ST1300 and the bars are odd sized.  This is more an application issue than a product issue.  I don't know if anything will hold well, so I bought this thinking the \\"grabby\\" strap would work for me.  Not so much, but again, I have odd handle bars.  It does get hard to pull the strap hard enough to get it sticking in place without feeling like I'll break it.