MySQL: Finding the records in one table that are not in another table

OK, this’ll make users of “proper databases” cringe but because MySQL doesn’t support sub-selects you can’t do the most obvious way of selecting records in one table that aren’t in another. Here’s how it’s done, with a clear explanation of why it works!
select po.id
from po left join pn
on po.id=pn.id
where pn.id is null

Unfortunately, I can’t figure out how to filter the second table as I don’t want to select from the whole table, only a subset. Anyone solved this?

S60 Python – on your mobile!

It looks like Python may be making it’s way to a Series 60 mobile phone soon! I may actually learn how to code in Python if this becomes available!
On that note, I may buy a new phone. The keyboard on my 7650 is getting cranky, some keys need to be pressed hard, others print characters twice. I could take the phone apart and clean the keyboard but now the plastic cover on the thumbstick/joystick thingy is coming apart. If I buy another phone, I’d like another Symbian device – Triz really is a great Tetris clone that I’d miss. Now, if I could only get a version of Go! for the phone I’d be happy and content.