Sure... slice them thinly and lay the pieces on paper towels to absorb the juice. After a couple of days, pick the seeds out and dry them further before storing them... A word of caution, however. If they were hybrids, as most are, they may not grow true to form... just a toss of the dice to see what your get. Best of luck!
Every time we use our harvested compost, we always get lots (and I mean lots) of tomato plants growing all over the place! Last week I stopped counting when I reached 50 (not my age!! I wish). Gave some away to neighbours, and my mum has some on her balcony. Guess when I do a bit of gardening this morning I"ll find some more......:0)