As I once again switch from one long-term contract to another, I see again a fresh batch of new faces. As usual, there is a wide selection of capabilities and experiences with the new team.
As an architect and senior developer, it is part of my profession to mentor those with less experience. Often this is not part of the job formal description. That doesn't alter the fact that it is a benefit to the team to provide guidance here, give a nudge there, be a sounding board, get someone to step through their reasoning, and what-not.
One of the things I see, going from client to client, is that there is a wide spectrum of what organizations will do for their employees in the area of professional development. Unfortunately I see less and less professional development efforts as the years go by. And for those who are contractors as opposed to employees, there is (not surprisingly) typically none provided by the organization. Indeed, in chasing the bottom line, companies often force people into silos, use them for a narrow set of skills, and throw them away when that particular silo is no longer needed.
One thing I figured out years ago is that in this industry, if you aren't always learning something new, you will soon find that you are obsolete. That doesn't mean you always have to jump on the latest fad technology and force it into production on your project, but you should at least familiarize yourself with it. It doesn't even have to be in the area in which you're working. Do you develop web applications? Familiarize yourself with how to run an IPv6 network. Do you manage a DNS infrastructure? Learn about continuous integration. What it is doesn't matter too much: Find an interesting-looking thread and pull on it. Try to pick a new thread every three to six months.
Something else I've noticed is that there are a lot fewer people reading professional journals than I would expect. If you're not already members, I would strongly recommend checking out the Association for Computing Machinery [acm.org], or perhaps the IEEE [ieee.org]. Both have extensive publications and digital libraries, and are excellent sources for keeping up on what is happening in the industry and acedemia (and in more depth than the general press, including the majority of the technical press).
For those who are already members, consider this: I will sometimes take my journals in to the client site after I'm done with them, remove/obliterate the mailing labels, and leave them in the lunch room frequented by developers and operations staff. They get read, and sometimes those organizations consequently get new members.
If you can afford it, try taking in a conference once in a while. Go to the social events. Mingle. If you can't afford a conference, look into the technical user groups at your local university.
Read. Expand your mind. And in five or ten or twenty years, when you feel like saying "get off my grass", you will realize that (almost) ALL of it is your grass, and now it's yours to cultivate.