My normal last day consists of a late flight.
I do a park in the AM, and then relax at the pool, eat dinner, and catch the DME to the airport.
I have never requested a late checkout.
1) Check all of your checked bags with RAC in the AM
2) Pack a carry-on and a bag with change of clothes, swimwear, a plastic bag for the swimwear, a comb/brush, and if you want any soap/shampoo/etc (remember TSA rules though). Leave these with bell services.
3) Go enjoy a park
4) Come back, get your swim bag from bell services.
Now here is the 'secret' - Depending on the resort there are showers / locker rooms available. Some are better than others. If you are not a DVC member, you may have to pay $10 or so to use the gym for the day (that entitles you to the locker room too) The locker rooms in BC/YC/WL are very nice. SSR used to have the downright BEST locker room - you used to use the Spa one (sauna, whirlpool, fresh fruit, robes and slippers, complimentery razors/combs/soap/toothpaste/etc, bathing suit spinner) but I guess too many people were using it, so now there is no access unless you are actually getting a spa treatment. There is now a shower and lockers available on the first floor of the spa building (but not in the spa). I miss the SSR spa locker room. I would come back from the park and swim, then sauna, shower, shave, brush teeth, get dressed, eat dinner at the Turf Club, and be totaly relaxed on my DME ride to the airport.
-dave