I came across this little snippet of code* to find the next power of 2 and found it quite helpful – from what I understand it's also very efficient compared to other methods.
public int NextPowerOfTwo(int inInt) { inInt--; inInt = ( inInt >> 1 ) | inInt; inInt = ( inInt >> 2 ) | inInt; inInt = ( inInt >> 4 ) | inInt; inInt = ( inInt >> 8 ) | inInt; inInt = ( inInt >> 16 ) | inInt; inInt++; // Val is now the next highest power of 2. return inInt; }
Link to original article regarding technique and actually a more detailed explanation of the method – Acius' Snippets.