I have been faced with this dilemma recently on several occasions and I was wondering what others do.

I usually try and get the most miles in any given account with the idea I'll use them for something someday. I don't fly enough for business anymore to get status (on any airline) so I try and maximize miles from personal trip expenses and non-flying accrual methods.

CO vs. NW

After reading both of these forums there are usually a fair number of bonuses being given if you sign up for them. I am a member of both OP and WP. I have more miles in WP but more flexibility flying CO (from IAH) If I have CO flight credited to WP then I lose out on CO bonuses and vice versa(NW flights credited to OP). What do other FT members do? Could apply to DL and UA too.

HP
I joined Flight Fund recently because I had 2 stays in Vegas. One at Mandalay and the other at Luxor. Recently they started giving Flightfund miles there (350 and 250 respectively). I probably wouldn't have joined FlightFund but I hated to lose out on something (even though some might argue it has minimal benefit if I never use it again.) Now I might need to fly HP for business and could get bonus miles in that account if I credit it there but just flight miles if I credit to CO (before that partership ends).

Do you take the credit as a partner in a program you favor or go for miles + bonuses in a new program you might rarely use?