Veilside R33 i am in the exact same problem, 200mb per month is not fun. I could spend the extra $30 for unlimited downloads but i prefer to save up for something better in the future.
Let your dad use the internet during the 28.8kbps cap, tell him about the cheap international calls he could make with VOIP, the webcam convos he could do with friends/family overseas? and the wide range of international web radios he could listen to. All these use up a lot of bandwidth and if you get him hooked on any one of them, say hello to unlimited cable
If he still disagrees get unlimited cable. I have already used up 5mb in 30minutes by talking on MSN and viewing this forum.
A good program to monitor your optus usage is located here: http://optus.larcos.com.au
Try the 200mb limit for one month and if your not happy just upgrade.
- Patrick