Reporting
Although splitting tomatoes

Although splitting tomatoes can sometimes be caused by fluctuating temperatures, they are more often caused by uneven watering (including drought/heavy rain), especially during the late stages of ripening. Some varieties are more susceptible than others. Try to be consistent in your watering and water deeply; adjust during dry periods and with heavy rain. Provide mulch to conserve moisture. If you had a dry spell and heavy rain is predicted, you might harvest your almost-mature tomatoes to catch them before they split; they'll complete their ripening on a windowsill. Harvest split tomatoes as soon as possible; those left on the vine may be subject to insects and diseases.

 

As for the lettuce, it sounds like they might have been attacked by slugs or snails. These pests come out at night to chew vegetation, leaving slime trails and large ragged holes in leaves. Remove any mulch around your plants where these pests like to hide. Pour beer in a small plastic container and sink it in the soil near your plants so that about 1/4 inch of the rim is above the soil. The slugs/snails will drown in the beer. You can also place boards around, where the pests will congregate, and you can then dispose of the pests the next day. For more information, see:

http://www.almanac.com/content/slugs