I applied to 7 Computer Science PhD programs (usually theory, algorithms or networking): 
  
Princeton 
Columbia 
Cornell 
MIT 
UCB 
UCSB 
Caltech 
  
  
Background: I've had 3 years of research, 4 strong LORs (2 from significant research contributors, i.e. TR35 winner and Vice Dean of Research), 3.95/4.0 GPA, 2 summers at major mobile chip company, I've taken grad courses, 1 submitted paper, one REU. 
  
However, I've had only one interview (UCSB, seemed very positive) and have yet to hear back from them regarding admission. I've also been rejected without any explanation from Cornell, Princeton and UWashington. It seems like I aimed too high, but the schools I applied to all had researchers whose interests aligned with my own. 
  
Is there anything that I can do at this point to increase my chances of getting in at least somewhere? If not, is there anything I can do to understand the weaknesses in my application/why I wasn't admitted? 
  
Thanks for any help,  
-Alex