In our church, we made it easy for new members to start donating and become pledgers when they joined instead of waiting for the annual pledge time. It has been very successful and handles the problem of the normal loss of pledgers during the year. The last two years, the pledges and donations from new comers exceeded the losses of losing pledging members for whatever reason.
JimRob has always taken a dim view of having a donation link at the top of the latest article page and the latest post page.
For about a year proceeding December 2,000 I tried to raise a little extra for FR every month. Since that December we basicly decided to go for a three months cash need every 90 days. It has been working very well.
Any Freeper can post the donation link on any thread through out the intervening months, when the subject comes up and it seems appropriate.