making a look-a-like list

I need to know how to add two people to a list, but list them as one item.

You might just have to list them both one after another, including a picture of each in their respective notes. I don't think that will detract from the list's quality. =)

Also, you could consider creating a section for each pair so it would be more clear they're look-alikes.

I know your list is likely to contain many different look-alikes, but just in case you want to be inspired here are some other really good look-alike lists:

Miss Audrey's look-alike
Miss Marilyn's look-alike