You need to have high PR back-links that are relevant to your field. However you also need to make sure that you keep your site clean and free of any black hat type techniques. Make sure you don't receive any links from spamming or unethical sites like porn or warez sites.
If its a wallpaper site as you say, you must first submit your individual pages to most of the social bookmarking sites and get atleast one backlink everyday. This will make your PR stronger.
PageRank is a mathematical model that works basically to determine the amount of backlinks to your site and the quality of those backlinks. So the solution? Get more backlinks from sites with as high PR as possible; that's pretty much the only way to raise a site's PR. Simon
You can add meta tags, this helps a lot. Another thing is building back links, try to exchange links with other sites similar to yours, comment on blogs, post in forums but don't spam. Google loves updating! Try to update your blog as many more times as you can!
Submit guest posts on many blogs. Also submit it to directories. Write good quality posts. Also try link exchange. I think guest posts is the best way as it also gives you free visitors too! Contact me for link exchange or if you want to guest post in my blog. I don't have a very high PR blog, but you can get many of my visitors. BTW, I won't suggest posting content in Digg, Etc. as they mostly give no follow links.
You should add quality content on a regular basis and continue working on link building. Your Page Rank will grow.
Why are you worrying about the PageRank? Google has also stated that Webmasters should not consider Pageranks thats why they removed it from Google Webmasters Tools Section.
PR is mostly back link related, so just keep getting quality back links. Other than that you can keep adding quality content to your site, and that will naturally build your back links as the more quality content that you have on your site the more people will naturally link to you and want to visit your site.
Google Page rank is based on back links. Back links are Links pointing to your website from another website. The more back links you have the higher your PR will be. 1. Join forums, forums are a great way to achieve links to your website. In most forums you are allowed to have a signature and in your signature you can put a link to your website. But another important note to look on is making sure the forum is somewhat related to your website. You will still get credit if it’s not, but if it’s related to your website than you will be accomplishing two tasks at once. You will be advertising for your website (bringing in targeted traffic) You will also be building your websites presence. Your websites presence is very important to your survival. The more people see, or hear about your website the more credibility you will have and this increases your chances of having these visitors come back and possibly become leads. 2. Submit to search engine directories. Search engine directories are a good way to get a free link to your website. They also increase your chances at being listed higher on popular search engines like Google, and overture. Most search engine directories allow you to submit to their website for free. This will allow you to increase your web presence by being listed on another search engine, and it will also be a free link. Remember the more links you have the higher your PR will be 3. Using ezine ads (or newsletters). Creating an ezine will probably be the most beneficial step you can take to increasing your web presence. When you create an ezine you will be able to keep visitors coming back to your website for more by using signatures and giving special deals. Ezine’s will also allow you to increase your back links. By creating an ezine you can submit your information about your ezine to an ezine directory. This directory will than link to your website(thus giving you a free link). 4. Creating and publishing articles. Articles are an easy source of generating new traffic. You can include your signature in your article. This will bring in more traffic from article submission directories. Your signature usually consists of 4 to 8 lines. Usually the first line would be the title of the website that you are trying to advertise. The last line would be the link to the website and the lines in between these would be a sales pitch to draw your viewers into your website. 5. Links from related websites. Gaining links from related websites can be one of the most frustrating tasks you can attempt.
Keep the process of building backlinks in regular practice through > article submissions > directory submissions > social bookmarking > press release > Forum posting > Classifieds Have a check whether your site is up to date by analysing other site in the same domain as of yours..