Cheapest way (not car) for visit visa extension? (Dubai)

Hi there...

I'm an Australian citizen arriving shortly in Dubai on a visit visa and would like to make sure I know what to do in advance to extend my visit visa before 30 days is over.. (No doubt I won't have a residence permit for sometime while I'm on some kind of probation if / when I get a job)...

My questions are..

- What is the cheapest way for a non-driving person such as myself to extend their visit visa? Apparently I can fly to Oman is this correct? Any suggestions for airline companies or other ways of transport to get to Oman quickly without needing to drive a car?

- Where in Oman do I go to get the visit visa extended? Is it a relatively quick and painless process to get the extension of the visit visa?

- Can I return the same day or is it usually require at least 2 days to do it?

Thanks in advance!

Boa =)