These are some of the tools and features that I find myself using on a regular basis when creating images for the web. These include using the slice tool on images to decrease page load times and using pre-set effects that save time when creating forms or menus for your site.
20 Things About Photoshop You Have to Know - Image Maps, Web Photo Gallery and Paste Into (Page 2 of 7 )
Image maps are very similar to slices in that you can use them to create roll-overs and hyperlinks. The main differences between slices and image maps are that slices must be rectangular, but image maps can be any shape. They are used only in Imageready, and have no effect on image download times.
Web Photo Gallery
This time-saving function can be found under File -> Automate -> Web Photo Gallery… and can be used to quickly put together a high quality, gallery of images in HTML format. You simply select a source directory, a target directory, and let Photoshop do the rest. It creates as many web pages as needed to include all of the pictures in the source directory, which are presented in a tabular layout of thumbnails. Additional parameters such as page titles and ALT text can also be specified. It even makes each image clickable and loads the full size version of the image in a page of its own when the thumbnail is clicked! This can be used to quickly create a product catalogue or portfolio.
Accessed via the Edit menu, this function inserts an image into another image, and crops the inner image to make it appear as if inside the outer image. For example, you could draw a rounded rectangle 100 pixels wide and 20 pixels high and then draw another rounded rectangle 40 pixels wide and 20 pixels high directly on top of it. You could then use the magic wand tool to select the area inside the smaller rectangle, and paste a photograph into the selected area. Now only the area of the photograph within the smaller rectangle is visible. Combined with some text, this makes an excellent web page heading.