It seems that someone did a complete redesign around mid January. You
can see some of the old design at http://web.archive.org/web/20070823193356/http://www.gadgetguy.com.au/
. In general, the best practice would be to have all the old URLs 301
redirect to the appropriate new ones. However, in this case, there
were a few things done in a suboptimal way:

1. Old URLs are 302 redirected to the homepage

2. For a period of about 3 weeks, it looks like you had robots meta
tags with a value of "none" across the site.

3. Until recently, many URLs had many keywords and spaces in them. For
example, you can see this on
http://74.125.39.104/search?q=cache:xWJcPWZfH8MJ:www.gadgetguy.com.au...

It contains a link like this:
<a href="photo-and-video-photography digital camera camcorder
videocamera handycam canon sony panasonic nikon channel 7 sunrise
australia-5.html">Photo and Video</a>

This ties in with my previous comment on long, difficult to understand
URLs. There are a lot of URLs that could end up showing that
content... this means we might spend a lot of time crawling through
URLs that are really just duplicates. URL length is not an issue
(apart from making it close to impossible for users to link to your
pages without copy&pasting the URL).

At this time, I would work on designing a very simple URL structure
that allows you to use relevant keywords in your URL so that the user
can understand what might be shown on the page. Also, you would want
to make sure that all canonical versions of your existing URLs
(including the old style ones) are 301 redirected to the new & simple
URL structure.

Hope it helps!
John