I spent about 3++ years in Tokyo from 94-98 as a Korporate Hacker :-/
Now I'm back in BrisVegas...mmmmm, Smart State:-)
>> I'm interested to see what the difference is between software development in Australia and Japan.
Depends on the company and industry you are working in.
>>It would be especially good if I could visit a small (10-50 ppl) company, bu anything might do.
Try contacting http://www.thetamusic.com/web/home/en/portal/home.html
Small company, but working in a key area.
I'm pretty sure they do a bunch of Java work but they might be pretty busy, as everyone in Tokyo is running around jazzed up on genki drinks and neon light overload.
As for things to do and see....
Lots of live music/Art/big city weirdness, but my old blues band (http://bbb.tlm.jp/
) still plays here once or twice a month: http://www.thefiddler.com/
Check out the magazine links on http://www.thefiddler.com/links.html
for current listings advice from the english what's on sites.
And for the best view of Tokyo check out http://www.tokyocityview.com/en/tokyoskydeck/index.html
at the Mori arts centre in Roppongi http://www.moriartscenter.org/
Also lots of interesting architecture in Tokyo: eg: http://mocoloco.com/tokyo/archives/000628.php#more
As for Oosaka...Kyoto is only 20 mins away by train and is worth the trip, especially to make the visit to any of the 40+ temple gardens, especially http://www.yamasa.org/japan/english/destinations/kyoto/ryoanji.html
(if only for a day)
Have fun...you'll need a holiday when you get back.
will save you a heap of money if you want to zip around, which is easy to do on Japans fast rail newtork.