I love and hate Ancestry.com. I love that they have made genealogy research online so easy. I hate that the information entered on the site is sometimes suspect. It's not a bad place to start, but it's not the be-all, end-all source they pretend to be.
With Veterans Day here, they are offering free military records on their site as a way to induce more people to get into genealogy. However, my favorite site for this type of curious searching is the WWII Memorial site. I knew my grandfather had served in the Navy in WWII, and a quick search on the WWII Registry shows his rank, the ships he served on, and the medals he earned. If you do a search on just last names and states (if your last name isn't too common), then you can easily find the records of his brother and cousins who also served.
And, it's free.