on to do list vs in to do list

Some examples from the web:

• Looks like Niklaus had a lot on his to-do list last night, and as for Hayley...
• Here's the first name on your to-do list.
• Hometown security is next on my to-do list.
• I guess you could say success was always on my to-do list.
• I'm now on her to-do list.
• On their to do list, I'm sure.
• If I interrupt it for FBI business, squealing on a fence will be right below joining Facebook on his to-do list.
• Darling, with those pecs, he was already on my to-do list.
• Why won't you sign the divorce papers? It's been on my to-do list.
• Not yet. It's on my to-do list.
• We've been meaning to break's on our to-do list.
• This wasn't high on my to-do list today.
• Daphne's got it in her head that she's just another girl on some to-do list.
• I'd love to, but I got four million other crazy people ahead of him on my to-do list, along with milk.
• It's been on my to-do list, sorry.
• Killing her's the next item on my to-do list.
• I've got one more thing on my to-do list, Ash.
• It's another check on my to-do list.
• I would not want to be number one on your to-do list today.
• Starting one was on my to-do list, but I never got around to it.

Some examples from the web:

• [Record invitation in my to-do list]
• We have friends, family, demons flying in, a to-do list getting no shorter...
• Display to-dos in flat list instead of a tree
• This plugin allows you to print out events and to-dos in list form.
• To display the to-do list view, press the To-do List View toolbar button, or choose the View To-do List menu item.
• So while Eli finished his ghost to-do list, I spent the whole day finding out passenger information.
• Looks like Niklaus had a lot on his to-do list last night, and as for Hayley...
• Kontact handles your e-mail, address book, calendar, to-do list and more.
• Your life's to-do list must be a baffling document.
• Here's the first name on your to-do list.
• I think you just gave me a honey-do list, which - wait.
• No, all I saw was an old pack of kools... and an unfinished to-do list.
• You just made my to-do list.
• Hometown security is next on my to-do list.
• I guess you could say success was always on my to-do list.
• I was simply autographing what I consider my most masterful to-do list yet.
• Somebody just went to the top of my to-do list.
• I'm now on her to-do list.
• The to-do list is clear on this count, I think we all agree.
• This is our to-do list for our wedding.