The links that Google shows in the link: command are, we understand, PR4 and up. They're valuable, but so are large numbers of PR3 and below links, which you won't find using this command.
Try alltheweb's link command for a different perspective...
Other things to look at depend on which page or pages you want to figure high in the SERPS. If you want your homepage to be your principal point of entry, be sure every page has a "home" link on it, to route some PR back to the top. If you want a selection of pages to appear in the SERPS, depending on the search phrases, consider a tree-style link structure where those pages are accessible from everywhere, but other, deeper, pages are only accessible from a single branch.
PR is not the be all and end all, but certainly you can, to a certain extent, funnel it where you want on your site, with the broad principle that the pages that can be reached from the most places on your site will accumulate more PR from your own site.
Another question is whether, when you scan the SERPS, you have non-important pages coming up fairly high. If so, you can perhaps change your link structure to give them less PR.
And now over to other readers for yer more ideas!...