Leviticus 27

This chapter was by far the most strange, or at least the most foriegn, part of the Bible I've ready yet. I know that probably sounds like an odd way to refer to any part of the Bible, but I'm currently a bit weirded out by it - especially verses 28 and 29:

"But nothing that a man owns and devotes to the LORD - whether man or animal or family land - may be sold or redeemed; everything so devoted is most holy to the LORD. No person devoted to destruction may be ransomed; he must be put to death." (NIV)

The whole idea of devoting something to the Lord by a vow in this chapter seems disconnected from the preceding chapters, but assuming that there was a good reason that people would do this then I really don't get the last line quoted above. Did people really dedicate themselves or their family members to God with the result of them being put to death? I truly hope that something is just not making the translation to English clearly, or that there was a cultural understanding about this which we simply lack today. I know that many times in the Bible people devoted children to the Lord's service, but they all were simply servants of God during their lives - so what is the "devoted to destruction" bit about? I consulted several translations and tried to find online commentary, with little beneficial results. If anyone out there has some insight on this, or can point me to a good resource for more info, I would appreciate it :/