When I tell people about grants they could get to help them work on open source/open culture stuff, sometimes they are surprised because they didn't know such grants existed. Here are some of them!

Grants with deadlines:

• Urgent: August 1st is the deadline for the Knight Prototype grant which "helps media makers, technologists and tinkerers take ideas from concept to demo. With grants of $35,000, innovators are given six months to research, test core assumptions and iterate before building out an entire project."
• Also coming up fast: August 4th is your deadline to apply for the Open Society Fellowship, which gives you about USD$80,000-100,000 to work on a project for a year.
• September 30th is the deadline for Individual Engagement Grants applications. IEG projects "support Wikimedians to complete projects that benefit the Wikimedia movement. Our focus is on experimentation for online impact. We fund individuals or small teams to organize, build, create, research or facilitate something that enhances the work of Wikimedia's volunteers." The maximum grant request is USD$30,000.
• If you're a woman working on a tech project that will benefit girls and women in tech, check out The Anita Borg Systers Pass-It-On (PIO) Awards, which range from USD$500-$1000. The next round opens for applications on August 6th.
• It looks like November 2014 is the deadline to apply for the Drupal Community Cultivation Grants: "to support current and future organizers and leaders of DrupalCamps, Drupal Meetups, Drupal Sprints, Drupal coalitions, and other creative projects that are spreading information within the Drupal community and educating individuals outside the community about Drupal... Grant awards will range from several hundred to several thousand dollars per project".

Grants that you can apply for anytime:

• Wikimedia project and event grants, which "support organizations, groups, and individuals to undertake innovative, mission-aligned projects that benefit the Wikimedia movement." Grants usually vary from USD$500-50,000.
• Mozilla makes grants ranging from USD$1,000-300,000 "to people and organizations we know, who are either working with us or in a closely related field" (specifically: Learning & Webmaking; Open Source Technology; User Sovereignty; Free Culture & Community).
• "The Python Software Foundation welcomes grant proposals for projects related to the development of Python, Python-related technology, educational programs and resources." It looks like they've granted amounts from about USD$500-10,000 in the past. If you want to run a Python-related hackfest/sprint, there's money for that too, to help with food, venue, and so on, for up to USD$300.
• The Sunlight Foundation offers grants USD$5,000-10,000 to open source projects that "make government more open and accessible".
• The Open Technology Fund makes grants "to support innovative efforts and new ideas from individuals and organizations globally defending freedom of expression online" and basically considers new "concept notes" (lightweight proposals) every two months. They are interested in making grants around USD$75,000-500,000.
• Wikimedia's "Travel & Participation Support funds Wikimedians to actively represent Wikimedia at events around the world." I believe most grants are for a few hundred or a few thousand dollars, to cover "travel, accommodation and incidental expenses." Many Wikimedia-specific events have their own scholarship programs as well to subsidize participation -- I know that a lot of open stuff events (e.g., PyCon, WisCon) also offer financial assistance in case you need it to get to the event.
• Edited (on August 4th) to add: TPF (The Perl Foundation) also offers grants for a variety of work that would benefit Perl in some way. TPF evaluates applications every two months, i.e., January, March, May, July, September and November. "Each grant is budgeted individually, according to the duration of the award, the recipient's financial needs, and projected expenses (travel, equipment, etc.) A typical amount for a 12-month grant involving some domestic US travel would be US$80,000." Past grants have been as low as a few hundred dollars.

This partially overlaps with the list that OpenHatch maintains on its wiki (and which I or someone else ought to update), and I have not even scratched the surface really. So anyway, yes, if you need some financial help to do better or more work in open stuff, take a look!