I suggest working to demonstrate interest and aptitude beyond PHP. (Even the famous PHP-using successes, Yahoo and Facebook, don't seem to be emphasizing it in their current job listings.) There are certainly PHP wizards and opportunities, but employers can fear that "just PHP" people are minimally self-taught, in isolation or on mostly non-tech teams, on small repetitive projects – and thus have bigger gaps in their experience, or more out-of-date habits, than people who've done a variety of things.

Personal projects, open-source contributions, or any work experience showing flexibility and use of new technology helps here. Simply indicating that you're eager to learn whatever new thing they want you to learn isn't enough, and can be seen as a negative: it's waiting for external direction, and they're hoping to see independent ambition/curiosity in the fields where they need help.

Similarly, avoid sending the signal that your main criteria is anyone who'll get you into the region at your minimum salary number. The employer will fear you have no special interest in their tech or market/products, and thus be harder to train up or likely to jump ship quickly.

Still, to a first approximation, every growing or well-funded company is always looking for people and often having a hard time finding them. Craigslist, the big job sites, and the monthly "Who's Hiring" thread on HN are all reasonable places to look for postings, but it also makes sense to look for companies with offerings you admire using technology you want (and have readied yourself) to work with, and then look for listings on their sites or ways to get the attention of their existing devs. If you're in the area, attending the meetups/networking events for your target technologies will also help you know who's using it, what they're doing, and what for what roles they're hiring.

Good luck!