Hi Tigerbelle
Unless the situation has recently changed, the Friends Association do the look-ups and make a charge.
You may get away with a free look-up as you're in Australia and transferring funds could be problematic.
Depending on the years you require, transcriptions of some of the registers are at the London Metropolitan Archives (1833-1872).
I'm currently doing look-ups at the London Metropolitan Archives (see my posts at the top of the London & Middx boards)
If what you are looking for falls between these dates, post another message with the names you are looking for and the dates. I'll then add you to my look-up list.
Dawn