my older one is going to be 4 in June and my younger one is 14 months now
i watch both of them alone Monday nights (my wife gets home around 9 and i get home around 6) and when she goes to the gym...other than that it have both of them on national holidays that my wife works (MLK day, Presidents day, etc.)
with an infant and a 2.5/3 year old it could be tough at times, especially for my wife
first time i was home alone w/ both she thought i was going to have a bad day but it went smooth, she was even a little bothered that i had such an easy time w/ them
other than toys, ipad, tv...try to get the other one interested in helping and interacting w/ the baby as much as possible
it will get easier as the little one becomes more idependent...sitting up, crawling, walking
for awhile the worst part was when the older one would be rough and spiteful but she's come around the bend as she's approaching age 4
still plays a little rough but not intentionally hurting the baby...if it's on accident she says sorry to her immediately and gives her a kiss