My PFD has plenty of storage space and attachment points which I put to good use.
http://www.stearnsflotation.com/Stea...-P1575C10.aspx
I carry a full-size dive knife and a small, lightweight safety knife on the front. On the left shoulder strap I have a white strobe and whistle. I've got one of the small Pelican waterproof flashers on the front. The right shoulder has a carabiner attached to a lifting strap that attaches to the back of the PFD. I keep my Standard Horizon HX850S DSC VHF radio/GPS clipped to the straps on the right side. Inside the front pockets I have 4 Starblazer flares (vacuum sealed to keep dry), 2 chem-lights, two Power Bars, Chapstick and a small container of zinc sunblock. I keep my fishing license in the interior pocket. I should keep some water in the PFD, but it is bulky enough already.
Because I AM a safety nut I also carry a CamelBak with additional water and survival gear (extra DSC radio, Garmin eTrex GPS, flares, smoke signal, chem-lights, Power Bars & signal mirror). I keep this CamelBak clipped on the back of my seat.