After a media go-round exposing charity administrative skims in the '70s, I decided all my charity should be local and under my direct control. I'd hear about a needy situation, do some research, and contact the treasurer of my church to give my contribution directly to the affected party. (This, in addition to my regular contributions when they passed the plate on Sundays, of course.)
That way, the entirety of my contribution, except maybe for the church's postage or the Deacon's gas to deliver it, went to where I wanted it to go.
I hated to be hardnosed about it, but the only bigcharity.org contributions I made were at work during the usual United Way campaigns, where they "needed" 100% contributions to "win" a back-patting mention and certificate.
I usually contributed a whole $1.00 and designated one of the NRA programs as a recipient --just so our division could win the 100% award*. (United Way allows you to designate the destination charity. But you have to press on them a little to find this out and get a listing of the organization codes to "route" your contribution.)
Terry, 230RN
*Sometimes we did and sometimes we didn't, so I guess there were other skinflints in the Division as well as li'l ole me.