The simple answer is do it for the experience. Say it takes you a year to build this intranet based system, when you finish it, you will have several advantages.

• One, a full year of web and database development and design.
• Two, a likely much better job market.
• Three, project management experience.

My advice is to suck up, take it in the you know where for a year, and in the end, look for a job elsewhere inside the company or outside.

You first mission, if you decide to accept it is to begin the first step of a project -- managing expectations. You will not be able to work full time on two projects at the same time. Give a base estimate of how long you think it will take based on the information you have. Let them know how long it will be before you can even start on the new project, assuming your current projects go as scheduled. Once you get the project, run with it as if you are the project manager/analyst/programmer all in one. This experience will make you much more valuable than the typical person with 3.5 years of experience.