For the past 8 months this has been my constant companion. 
It's like that egg project from high school where you have to keep it with you at all times in some lame attempt to show teenagers what it would be like to have a real kid. If they're really trying to keep teenagers from getting pregnant, this is a much more effective deterent than a stupid egg. I am, for all intents and purposes, a human milk machine. A cow. A meal ticket for a growing infant.
I'm part of a small demographic of mothers who exclusively pump (EP on the Mommy boards). There are several reasons that women do this, and they're all applicable to me. First, I work full-time. Unfortunately, I'm not independently wealthy, nor am I married to a well-to-do man. I married someone who chose his family over his career (rightfully so), so he's not now, nor will he be in the near future, in a position to allow me to be a kept woman. Due to the strict policy against having a nursing infant attached to your hip/breast at work, I'm forced to put her in daycare. This restricts my nursing abilities.
Second, even if I stayed at home, I'd have to pump. Let's just say I don't have Jennifer Anniston's overachieving nips (like you haven't noticed), so I am physically incapable of nursing Sophie. I didn't know it was a problem until Trevor was born. I had intended to nurse him but was told in the hospital that I couldn't and would have to use a shield while nursing for him to be able to feed. I made a valiant effort, but the shield was such an awful experience that I gave up trying to nurse after 6 weeks. I didn't even attempt to nurse Victoria, because I didn't think it was possible. When I was pregnant with Sophie, I was determined for her to be breast fed, and I did a ton of research on how to handle inverted nipples. It turned out that I could have nursed all of my children, had I done the proper research and gotten a decent breast pump from the beginning. I still carry guilt from not nursing Trevor and Victoria and am convinced every time one of them gets sick, it's due to the fact that they were formula fed. (Insane- I know)
The other reason I exclusively pump and don't even nurse Sophie when I'm not at work is because Sophie has what is known as a vigorous suck. She latched on immediately after birth in the hospital. I was so proud and excited. Then, the feedings became more and more painful. I noticed my nipples were cracked and bleeding, so I asked to see the lactation consultant. She took one look at my war torn chest and said that I would have to either exclusively pump or use the breast shield due to the trauma Sophie was causing my nipples. The TRAUMA. I had traumatized nipples. That is not what I wanted to hear. I knew the breast shield would never work out, so I opted for EP'ing. And, 8 months later I'm still doing it.
That's not to say it hasn't been difficult. The first few weeks, you have to pump every 2-3 hours just to build your supply. Over time, you can drop pumping sessions, but it's months before you ever get to enjoy any real freedom from it. Now I'm down to 3 pumps a day, but that still means I have to pump once during work, which isn't always feasible when I have to meet with employees on a regular basis, and constantly have a shit ton of things to do. I also hate pumping right before bed, because there are so many nights when I'm exhausted and just want to crawl under the sheets, but I know I have a 20-30 minute session ahead of me. I have to confess that I do enjoy having it as an excuse to relax, though, since I can surf the Net while doing it, but I can't do much else. It forces me to take breaks.
As much of a pain in the ass as this whole process has been, I have to say that I have a complete sense of pride when I see what it's done for her. She's 8 months old in 12 month clothes. She's the size now that her brother and sister were at their 1st birthdays. I love chubby babies, and boy is she ever a chunk. Just look- see the results for yourself.
I'm definitely in favor of a mother choosing the best option for her. I understand why someone would choose to formula feed, and I never think a mother should be guilted into breastfeeding, since the last thing you want is to resent your baby for a decision you feel pressured to make. I just want people to know that there is an alternative to breast and formula feeding, and it is possible to succeed in the long-term. I hope to keep it up until she can go on milk at age 1, but I'm just thrilled to have made it as long as I have.