Inclusion Criteria:

1. Patients with pathologically confirmed advanced or metastatic cancer that is refractory to standard therapy, relapsed after standard therapy, or who have had no standard therapy that induces a CR rate of at least 10% or improves survival by at least three months.
2. Patients must have tumor tissue available, either from an archival specimen, or from a recent biopsy, to be analyzed for EGFR mutation. Patients must sign consent for the umbrella protocol prior testing for EGFR mutation. Patients will be eligible if they have an EGFR-sensitive mutation, OR if they have an EGFR-resistant mutation, OR if they do not have an EGFR mutation, but have benefited from EGFR inhibitor therapy (including either >/= 4 months of stable disease [SD] OR a >/= partial response [PR]).
3. Measurable or non-measurable disease at baseline for patients to be enrolled during the dose-escalation phase; measurable disease for patients to be enrolled at the dose-expansion phase.
4. Patients enrolled in the MTD cohorts must be willing to undergo tissue biopsy (and an accessible biopsy site). Pleural effusions and ascites will be acceptable in lieu of tissue biopsies, if available.
5. Patients must be >/= 6 wks beyond treatment with a nitrosourea or mitomycin-C, >/= 4 wks beyond other chemotherapy or radiation therapy, and must have recovered to </= Grade 1 toxicity for any treatment-limiting toxicity resulting from prior therapy. (Exception: patients may have received palliative low dose XRT to the limbs 1-4 wks before this therapy provided pelvis, ribs, sternum, scapulae, vertebrae or skull were not included in the XRT field).
6. (continued from above) Also, patients who have received non-chemotherapeutic biological agents will need to wait at least 5 half-lives or 4 wks, whichever is shorter, from the last day of treatment.
7. ECOG performance status </= 2 (Karnofsky >/= 60%)
8. Patients must have normal organ and marrow function defined as: absolute neutrophil count >/=1,000/mL; platelets >/=75,000/mL; creatinine </= 2 X ULN; total bilirubin </= 2.0; AST(SGOT)/ALT(SGPT) </= 3 X ULN; Exception for patients with liver metastasis: total bilirubin </= 3 x ULN; AST(SGOT)/ALT(SGPT) </= 5 X ULN.
9. Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 30 days after the last dose.
10. Ability to understand and the willingness to sign a written informed consent document.
11. Age >/= 18 years, male or female patients

Exclusion Criteria:

1. Patients with uncontrolled concurrent illness, including but not limited to: ongoing or active infection; uncontrolled endocrine diseases [e.g., diabetes mellitus (Hba1C > 8), hypothyroidism (serum TSH >10) or hyperthyroidism (serum TSH <0.1), adrenal disorder); altered mental status or psychiatric illness/social situations that would limit compliance with study requirements and/or obscure study results.
2. Uncontrolled systemic vascular hypertension (systolic blood pressure > 140 mm Hg, diastolic blood pressure > 90 mm Hg on medication).
3. Patients with clinically significant cardiovascular disease: history of CVA within 6 months, myocardial infarction or unstable angina within 6 months, or unstable angina pectoris.
4. Patients with colorectal carcinoma with tumors that demonstrate a KRAS mutation.
5. Pregnant or lactating women
6. Patients with a history of bone marrow transplant within the previous two years
7. Patients with a known hypersensitivity to any of the components of the drug products.
8. Patients who will be on treatment arm consisting of erlotinib and dasatinib should not be taking any drugs that are potent inhibitors or inducers of CYP34A
9. Patients with active or untreated brain metastases, or patients with leptomeningeal disease.
10. Patients unable to swallow oral medications or with pre-existing gastrointestinal disorders that might interfere with proper absorption of oral drugs.
11. Patients with major surgery within 30 days prior to entering the study.