We wanted to get some images into WordPress side by side and with captions, but also in categories on the same page. So WordPress’s new (since 2.5) built-in gallery would have worked just fine if it weren’t for the different galleries on the same page (and maybe that’s possible, but I just don’t know how to do it). So using just the new-ish image browser, I put captions onto images and inserted them side-by-side (align: left) on the page then categorized with just text (heading text with a clear line break to get specific). But inserting images into the posts using the visual viewer was a bit cumbersome, so I flipped back to the HTML viewer to see better where I was inserting the images. NextGen gallery probably would have worked just as well, but I’m always trying to not use plugins if I don’t have to.