Landscape email and SMS support is coming in OS 3.0 - as is MMS, so you might aswell wait as there isn't a decent free one out at the mo (jailbreak app SwirlyMMS is $8 for a license, and the free one in the App Store you have to buy credits for as it won't work with network tariff's) OS 3.0 will also include updates for the SMS app to allow forwarding of messages and singular message delete

All in all, 3.0 is a major step up for the iPhone OS!