The way I do it is to take a full backup every day. The log backups are taken every 30 minutes. Than again, I don't have any hugs databases where a full can't complete in the time I have. I also have enough disk space to keep 5 days worth of full backups and the associated log files.

If you have enormous databases that you can't do a full backup on, I encourage you to explore what Jeff mentioned with the file groups and partitions. Of course, for the partitions, you need Enterprise Edition. Jeff has done a presentation on partitioning that's truly awesome. He really gets into how things work. If you get the chance to attend a SQL Saturday where he's giving that presentation, it's well worth the time and brain power to attend.

Whatever backup scenario you implement, let me stress the importance of testing your backups by restoring them to somewhere. If you don't test them, you'll never know if they're viable until you really need them. That's too late to learn that they're no good. The only way to be sure is to test. I don't know who said it originally, but I've heard the phrase "You don't need a backup strategy. You need a recover strategy." This shift the focus from the backups to recovery. Yes, the backups have to be in place, but you also have to know they're good.