You know, it's interesting; I think the only points I have with Hilton are from dining with them (I have no idea if those expire the same way as Hilton points earned other ways, but probably)...and another question, do points earned by dining with Hilton count as "activity"?
I do try to keep track of these all in my head so that I don't lose points by forgetting to use them, though I have an extra special place in my heart for miles that don't expire (Skymiles, how I love thee). My question though was more about bonuses that hotels might give for signing up for their program while staying at their hotel (I could've sworn Marriott was running a promotion like that, where you get extra points if you sign up for their program while you're staying there).