The iPhone's pretty rubbish handling of PDF files can be a frustration.  There's no way to transfer the files direct to the handset - you have to email them to yourself - and the reading app is portrait-mode only and requires a lot of scrolling if you've got a wide document.  What's needed is a way to use the far better rendering in Safari, and that's just what's detailed over at Pimm.

To be fair, it's still not an easy solution - it requires conversion of the file to a data: URI format that Safari will understand - and there are a few steps including synchronizing your iPhone with your home computer.  It's certainly not something you could do on the move.  But, if there are a number of PDF files you regularly consult (technical manuals, brochures, contact lists, that sort of thing) then it might be worth going through the process with them.  Then you can use Safari's landscape mode and zooming tools.

Let's cross our fingers and hope for a proper Adobe PDF reader appearing soon.