In reply to tony:
> (In reply to Milesy)
> [...]
>
> It's largely a matter of choice. I very rarely use colons or semi-colons, because I don't think they make text any easier to read. They usually result in sentences getting more convoluted than they need to be, and I tend to prefer the greater clarity of full stops and tidy sentences.
It just depends on whether you wish to tie two subjects together or keep them separate. Neither of which can be accommodated by not using colon/semi-colon.