Fictional Expletives
I just discovered a nifty little resource for geeks who want alternatives to cuss words – a whole Wikipedia article detailing a slew of fictional cusses created for sci-fi.
http://en.wikipedia.org/wiki/List_of_fictional_curse_words
For example, instead of using the F-word, you might say flup, frag, frak, fraz, frek, frell, or even frinx.
Have fun!