LinkUp basic search: LinkUp's basic search is extremely basic, offering you the option to search by job title, keyword, or location. You can search by one of the three, two out of three, or all at once.
LinkUp advanced search: LinkUp's advanced search is available by clicking on the dropdown menu right under the basic search menu. You can search by company name here, as well as categories; there's also a "search methods" option: match any, match all, exact matches, or Boolean search.
Browse the sitemap: LinkUp offers all of their search options on one convenient page; you can check out employers (arranged alphabetically), locations, and categories here.
As you can see, LinkUp offers many search options for the job searcher. For more job search engines, check out the Top Ten Job Search Engines, and be sure to visit the excellent About Job Search site.