photostream too large for iPhone sync

Having filled my iphone to capacity, I urgently need to limit the number of photos stored on my device.  I have photostream enabled, with about 950 photos taken over the past 5 months.  I don't need them all stored on my device -- just the last month would suffice.  Can I limit photostream to sync only about 300 photos or so?  I like the feature but I miss having apps and music on my phone.