how to reduce cycles render time in blender
better hardware, learn & practice… outsource / use of farm 
There are sometimes ways to optimize materials to get slightly better render times, but it depends entirely on what specifically you’re rendering. Then of course there are the obvious general answers that any google search will give you for this question:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Reducing_Noise
Branched path tracing can offer speedups sometimes by selectively increasing only the sample types that are most useful to your render, but again this depends largely on what type of scene and materials you are specifically rendering at the time. http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Integrator
Otherwise, yeah, get better hardware, use a render farm, or learn to be patient. High quality rendering takes time, ultimately.
Reduce the number of lamps and don’t use geometry as a mesh light if you don’t have to. If you do use emitting geometry, turn off “multiple importance sampling” unless it contributes a lot of light to the scene.
Use the branched path tracer if you can. Once tuned in it usually produces clean results faster than vanilla path tracing (but not always).
Learn how to use node tricks to speed up shader evaluations. One of the tricks that has worked for me is setting up a node tree that uses textures and bump mapping only for the first light bounce, and after that it is a simple diffuse color. This cleans up the indirect light and speeds things up by quite a bit.
I used all three of these tricks to get a render from just under two hours to just under twenty minutes.
If you want to get really fancy, you can render a low amount of samples and then use the bilateral blur in the compositor to denoise the indirect passes and composite them back in. This works well but is a real pain in the *ss to set up and can blur details.
Also, don’t be afraid to mix the use of both BI and Cycles within a single project. Even within a single shot.
Cycles takes a very different algorithmic approach to the task of rendering, and IMHO that approach is “complementary to” what BI does. (And don’t overlook OpenGL, either.) Cycles produces marvelous “soft-box” lighting effects, although its approach can quickly become expensive and it can fail to “converge” upon a single, glitter-free solution, leaving you with “fireflies.” But, if you take the approach that “Cycles does not have to render the entire scene,” it’s very nice for producing components of the scene. Leverage the respective strengths of all of the rendering algorithms that are built-in and available to you: OpenGL, BI, Cycles. Become very good at compositing.
