I am attempting to build a classified ad list for internal use. I want an image upload column that allows users to browse to a local file instead of having to paste a URL, and then I need to display the uploaded image in the list. I initially planned on using a Picture Library as the obvious solution, but there will be cases where a user does not have an image for the item they are selling.
(This answer assumes you're asking how to implement a solution like which you're asking):
Best way to do this I think is to create a new Content Type which inherits from Page, and includes a PublishingImage column, and maybe some other columns for the details. Make the various columns for the details Optional or Required as needed.
When people create their classified Ads, they create a new page and fill out the details.
This means you'll also need to create a new Page Layout to let users edit the details, and to let you choose how to display the content. Your new Page Layout will be associated with your new Content Type, so that it makes use of the new columns that you have added.
Finally, you'll want to display the content, maybe many items in one panel. For this, you could create a custom Content Query Web Part which has some custom XSL which lets you display what (minimal?) details to show in this summary view. Paging (I think) isn't implemented in the default Content Query Web Part, so you'll need to search for methods on how to implement paging (I know Waldek Mastykarz has done it here: http://blog.mastykarz.nl/paging-content-query-web-part/).
You can do all this with only SharePoint Designer to help you, and the rest of the setting up being done within the SharePoint UI. Sometimes you might need to save files to your computer to edit, then re-upload.
Here's some links to help you:
Customising the Content Query Web Part with custom Item Styles: http://www.heathersolomon.com/blog/articles/CustomItemStyle.aspx
There is free SharePoint tool that allows to upload images from local disk and display them in SharePoint lists: http://sparqubepicturelite.codeplex.com