No artistic ability required

This picture had no artist. No one drew or sketched it. It was captured with a digital camera and with little more than a menu click, changed to a very human-appealing line drawing. Click on it to see the source image.
Photoshop "filters and effects" can be applied to any photograph. No artistic ability required. Here's an
article showing how to do these artistic transformations. The building photo and "drawing" are Figures 3-124 and 3-125.
It-can't-be-that-easy
These artistic effects do require some Photoshop skills, such as working with layers.
Often, the author begins an effect by duplicating the image on a layer above the original, applying a built-in effect to the duplicated image, then blending the top layer into the original (reducing the opacity or picking a "blending mode" from the "blending options" in the Layer palette combining the modified and original versions).
Expensive software
The cost of Photoshop may be too much for a hobby (half a thousand dollars?!), but if you have a digital camera and enjoy photography, you might consider buying and learning it.
Maybe you can pick up an academic version of Photoshop CS2 if you teach or have kids in school. Maybe with a new version (CS3) out this spring there will be deals on the current (CS2) version in the next few months. Maybe there's an extra unused copy (even if it's not the current version) floating around your company somewhere. If you might modify graphics for your blog or website and have self-employment income, it might well qualify as a deductible business expense.
Learning applications with dense UIs
So if you invest in the software, you might want a crash course in how to use it. I favor online video training like Lynda.com and VTC.com for learning software with as many dials and knobs and sliders as Photoshop or Expression Blend. Watching helps me ramp up quicker than just reading books and articles. Watching an expert in real-time conveys at a task-oriented level how to use the program--especially if you instantly see the results on screen.
I do buy lots of good computer books, and use them mostly for drilling down on a subject-of-interest, rather than reading them cover-to-cover when starting out. To me, a chapter in a well-crafted computer book has drama, tension, a bit of diversionary wit or commentary, then a thrilling finish showing the finished product. (Maybe I should get away on vacation more often.)
What are Photoshop Filters?
You can watch a free sample Quicktime movie from a subscription video training series:
[5 minutes to watch both movies]
Alas, these filters and effects aren't mentioned in the more wallet-friendly Photoshop Elements (under $100) described on the Adobe web site. Photoshop Elements
does have spiffy features like adding frames and backgrounds and making slideshows. (I don't know what spiffy means. I think it's the opposite of klunky.)