You're pretty much required to grab a Class 6 SDHC card for the 550D / T2i. For an awesome name brand you're paying around $130, and that's an awesome deal for that huge 32gb storage. Compact flash cards on the other hand, if you wanted speeds of 60MBS, you'd be paying several hundreds. Although Canon says you're not required to use 400x cards to shoot video, they say it will help with RAW read / writes + dumping that data down will be faster than ever. Right now Sandisk is running some rebates if you've got the cash to buy a couple of cards, or you can grab those same Rebate prices simply off eBay without having to mail anything in and waiting.
Wow, this is a great deal and just had to share with the visitors. We all run out of Video space with these high end DLSR's so getting a decent sized card at a decent price is hard to come by. Here's a great deal on a SanDisk Extreme that writes at 60MB/s. Not only will it be awesome fast for your camera to do Video mode, but these speeds help when you're downloading to your computer so you can get back to what you love doing most.