LINQ list to sentence format (insert commas & “and”)

Question

I have a linq query that does something simple like:

var k = people.Select(x=>new{x.ID, x.Name});

I then want a function or linq lambda,

Answer 1

Improving(hopefully) on KeithS's answer:

string nextBit = "";
var sb = new StringBuilder();
foreach(Person person in list)
{
    sb.Append(nextBit);
    sb.Append(", ");
    nextBit = String.Format("{0}:{1}", person.ID, person.Name);
}
sb.Remove(sb.Length - 3, 2);
sb.Append(" and ");
sb.Append(nextBit);