Losing a spouse is probably one of the most difficult times in a person's life. I know many widows and some have dealt with it in many ways. Some women never cleared out their husbands' closets because parting with their belongings was just too difficult. While others found having the belongings around was just too much -- meaning everyone needs to grieve in the way that feels right for them.
With regard to your question about celebrating the lives of the dead, the first that comes to mind for me is Dia De Los Muertos or Day of the Dead -- a festival around Halloween that takes place in Mexico and celebrates the union of families with their loved ones who have passed.
The ancient, indigenous peoples of Mexico (Purepecha, Nahua, Totonac and Otomí) believed that the souls of the dead return every year to visit with their living relatives. Marigolds help lost souls find their way back home or back to their loved ones. (Source: Mexonline.com)
While my mother hasn't embraced Day of the Dead with regard to my father, who was German and passed away more than two years ago, growing up in the Southwest, I wear Dia de Los Muertos jewelry (a necklace with a traditional Day of the Dead skull) to remind myself in my own way to respect and celebrate my father's life. Like Todd, I cannot imagine losing my spouse.
Perhaps there's a small but similar gesture to try. I would also like to know what you're doing that's working.