What's the best way to convert video for the iPhone?

[sofakng]

I have a whole bunch of videos in different formats and containers (xvid, mkv, divx, etc) and I'd like to convert them for the iPhone.

Is Quicktime Pro pretty much the best option? (eg. converting them all to h.264)

If not, then what should I use?

Also, how can I tell exactly what format a video is in so I can tell if it play natively on the iPhone without me needing to convert it or having to copy it to the phone and trying it?

EDIT: I'm using Windows XP/Vista by the way...

[thehotrod]

I'm relatively new to the iPhone and such, but I've used Handbrake with some success.

[Grassmasta]

You know, I hate to recommend something like this (as it could be used in the wronge way). But I've had much trouble converting media due to certain dvd codec issues. So, I've simply resorted to downloading torrents that are already converted (which is perfectly legal as long as you own the media).

Also, to find out what format its in, right click and look at the properties. If you look around on cydia, there are a couple of different media players that support more file types.

[ericidle]

I'm using this and its works great for my needs, both Apple TV and iPhone

Products of 4Media Software Studio - MP4 Converter, DVD to MP4/iPod/Zune