This is a phase 1, open-label trial of perifosine and paclitaxel administered either weekly or every 3 weeks in patients with malignancies for whom single agent paclitaxel is a reasonable treatment option. All patients will receive paclitaxel either at a dose of 80 mg/m2 on days 1, 8 and 15 of a 28-day cycle (Arm A) or at 175 mg/m2 administered on day 8 of a 21 day cycle (Arm B). Patients on both arm A and arm B will receive premedication with diphenhydramine 50 mg IV 30 minutes prior to treatment; ranitidine 50 mg IV 30 minutes prior to treatment and dexamethasone 20 mg IV at 30 minutes prior to treatment. The 1st cohort of patients on Arm A will receive perifosine orally at a dose of 50 mg per day for the first 21 days of the 28-day cycle and on Arm B will receive perifosine orally at a dose of 50 mg per day for the first 14 days of the 21-day cycle. On each arm, the perifosine dose will be escalated in subsequent groups to 50 mg bid and then 50 mg tid as tolerated. (See below) Alternating cohorts of 3 patients will be entered first to Arm A and then to Arm B. The perifosine dose escalation for Arm A and Arm B will be performed separately according to the following algorithm. For each arm, a maximum tolerated dose (MTD) will be defined as a dose that can be given without grade 3/4 non-hematologic toxicity in more than 1/3 patients. If 2/3 patients in any cohort encounter a grade 3/4 non-hematologic toxicity, an additional 3 patients will be added. If the dose is intolerable for >3/6 patients then the previous dose level will be declared the MTD for that arm.