Can you use those telstra bigpond adsl modems on a different provider?
Yes, I have never had a Telstra/Bigpond ADSL service. I purchased a second hand Bigpond Speedstream modem ($20) and had no problems converting it to suit my ISP. Siemens make the speedstream and you can download updated firmware if you need to remove all traces, but simply reconfiguring works too. Apparently some of the earlier modem had restrictive firmware, but that has been removed more recently.