Some are the charitable arm of for-profit financial services institutions such as the Fidelity Charitable Gift Fund, the Schwab Charitable, and the VanguardCharitableEndowmentProgram.
In late July the VanguardCharitableEndowmentProgram sent warning letters to 32 folks who set up tax-deductible donor-advised funds in 1998 but haven't yet directed a penny from those funds to an operating charity.
Indeed, donor-advised funds, both those run by community foundations like the Trust and those affiliated with investment firms, such as the Fidelity Charitable Gift Fund, the VanguardCharitableEndowmentProgram, and the Schwab Charitable Fund, are a fine way for folks who aren't rich enough to set up their own private foundations to funnel money over time to their favorite charities.