When creating a Contribution Page, you can enable a widget and copy the code to create a progress bar wherever you want. I'd like to do that with some personal campaign pages, so that they are all on the same front-facing webpage to show who is winning a fundraising competition. I'm not finding an obvious way to do that, but I expect it is possible.
I'm not sure there's an 'easy' way to do it (similar to the widget code for an entire Contribution page). In the past I've done something like it by writing a custom plugin (for Wordpress) that used mysql queries to pull data from active PCPs. I don’t believe there’s a fully operational API for PCPs yet - that would probably let you avoid writing queries yourself - there is however an unofficial API that you might find useful.