PENIS PUMP... Don't know what else to tell you aside from either 1) wife continue doing the kegels and/or 2) be content with your sex life as is if your wife is getting off most times and you get something out of it too.
I guess you could try one of those jelqing sites that people "swear" works to enlarge your crank. I think those sites are bullsh!t, but if you want to try it out go to one of those sites. I just did a google search for this one:
Penis Gym - Get the Penis YOU WANT. Don't laugh, but there was a thread on LS about this. I actually tried it out for a short period of time. Didn't need to but was curious. I don't think it works plus I think you run the risk of hurting yourself. But, if you're desperate enough...