Hacklabs are DIY, self-sufficient spaces based on the horizontal model of decision-making, they are "autonomous technology zones, spaces for learning, for making your own media, for the sharing and developing of free and not-for-commercial-use technologies and software, for battling surveillance and alienation, for ongoing projects and for using new forms of communication in direct action." 
A Sheffield Hacklab would be a space where hackers , Free software activists , social campaigners, and progressive activists of all varieties can get together as hacktivists; "Hacktivism is root. It is the use of one's collective or individual ingenuity to circumvent limitations, to hack clever solutions to complex problems using computer and Internet technology. Hacktivism is a continually evolving and open process; its tactics and methodology are not static. In this sense no one owns hacktivism - it has no prophet, no gospel and no canonized literature. Hacktivism is a rhizomic, open-source phenomenon." .
Practically the Sheffield Hacklab would be a space in the Matilda social centre  with recycled computers running Free software, it would be somewhere where you can bring your computer if it's broken, somewhere to experiment with wireless technologies, somewhere to learn to use Free software for making your own media, photos, graphics, music, web sites, somewhere to play games, and much more...
It should be a space that is used to subvert sexual stereotypes, somewhere where Gender Changers  workshops and Eclectic Tech Carnival  type activities can be held, "We want to help women feel confident enough to 'hack' their own way into northern and male domination of digital technology." .
To make this happen will take a lot of reality hacking, but we have a head start with a space and the kit from the G8 Indymedia lab  which has been donated by Lowtech . What is needed next is practical things, workbenches, furniture etc, it has also been suggested that we could try to run the lab on solar / wind power .
What next? There is a Matilda meeting on Monday 18th July , at that there will hopefully be an opportunity to have a Sheffield Hacklab sub-meeting, there also a Sheffield Hacklab wiki page, https://en.wiki.aktivix.org/Sheffield_hacklab and an email list will be set up soon.
Get involved! Together we can Hack Sheffield!