In my application users are required to select from a drop down, a list of projects they wish to include in their custom search. The easy part is that users can select one project to filter on or select them all but it gets tricky when they want to select more than one but not all. The only way I can think of doing this is to offer another option in the drop down "select projects" that opens a dialogue with a large list of check boxes, they then select the projects which is posted back to the filter query.
Although this might work it seems counter-intuitive and I'm hoping some other people might have some better examples of displaying large lists of check boxes that will be quicker to user rather than this adhoc process.
Any ideas on this would be great.