There are a few distinct ways you can tackle this:
1) Look into getting a quality cat sitter. Talk to friends with pets, people in your neighborhood with pets, people at your vet's office. The unfortunate thing is that you will have to filter through a lot of bad info, but eventually you should be able to find some really good pet sitters. I'd concentrate on getting info from people who you know are REALLY close to their pets. Vet offices can sometimes be misleading because they sometimes have a mutual backscratching deal. The young techs get pet sitting referrals by default and so aren't necessarily the best pet sitters.
2) Fostering: can you find someone who would be willing to have your pet as their pet on a part time basis? Say a friend of yours in the area. Unfortunately this solution has the same issues that the next one does: namely, cats are instinctively attached to their territory. A move, be it short or long distance, is always very stressful for them, unless they experience frequent moves and come to realize, "hey, my territory is not the source of my food and all the other goodies". This is easier to do with a young cat than an older one who has been in the same place for a long time.
3) Take your cat with you. Cats instinctively hate to travel but some people have broken them of that. If you start when the cat is relatively young and frequently take it to different surroundings, the cat should be conditioned to lose its strong natural instinct that territory is what defines well-being. There is a really stupid book on the subject (actually several) called The Cat Who Went to Paris. Basically the owner traveled a lot and took his cat wherever he went. I can't recommend the rest of the book, but the parts about his cat I liked. It may be of use to you.