The indie science fiction film has come a long way in the last 5-10 years. Technology has reached a point where money is no longer a barrier to getting fantastic effects and large scale ideas on a minuscule budget. You can watch two short films below that fit that mold perfectly: True Skin, which deals with body modifications, and Plurality, a film that takes place in a New York City dominated by a universal identification system that follows every person's slightest move.
Both films do a great job at what anyone who is making a "calling card" film should be thinking about: big ideas and fast execution. The first film, True Skin, written and directed by Stephan Zlotescu (who also did many of the effects), is interesting in that it uses a lot of real-world settings and people in the film, but augments them with 3D special effects. It's certainly one way to achieve a grander scale on a smaller budget, and it reminded me a lot of the film Monsters, which utilized real-life road signs and objects and modified them to suit the story.
Plurality, directed by Dennis Liu, did much of the same, shooting in public spaces on a Canon 5D and 7D, and creating the special effects on a small budget over a 2 year period. What's interesting about the two films is their extensive use of narration. For science fiction worlds which are different from our own, there definitely has to be some sort of setup for the audience to understand the world that the film takes place in. There is a lot of narration and inner dialogue in both films, and maybe it's a personal preference, but in my opinion, narration is hard to get right 100% of the time without a perfect voice and perfect dialogue, because you aren't able to look at a face and find the true meaning behind the words.
Either way, both films show that special effects on a limited budget are getting better and better, and we're going to see some very impressive low-budget features in the near future with mind-blowing effects.